Blurryeyed Loc: NC Mountains.

I don't know, I just purchased a Fuji X-T2 and am amazed by it. I also have two Canon full frames, 5DIV and 5DSR that I shoot BIF with. However the specs on the new Fuji X-T3 suggest that if the focusing system is as good as the Canons it already out preforms your 7DmkII. I can't advise you on the continuous focusing ability of the Fuji because I purchased mine to use with my manual lens collection and own no Fuji lenses to test the focusing system with. Like Canon did with the 5DSR Fuji also did away with the anti-alias filter so your images are crisper and more detailed. I'm not going to make the change because I have far too much invested in Canon glass, but were Canon to offer a mirrorless competitive with the Fuji it would be a serious consideration, from what I have heard the Canon R is just not there yet.

You may change your mind on mirrorless before the Canon 7DIII comes out, the mirrorless cameras are amazing and for me and my old lenses, focus peaking is totally worth the purchase price.

kymarto Loc: Portland OR and Milan Italy

There is the fact that An EVF gives you a much better idea of your exposure than an OVF, and gives you critical focusing ability that DSLR users only dream about. There is also the fact, though, that there is no viewfinder lag with a DSLR, which is still a significant problem with critical timing in almost all mirrorless cams to some degree.

traderjohn Loc: New York City

I think mirrorless camera's are being part of the move forward on every level. What about them makes them inferior? The use of cell phones will have a bigger effect on DSLR and mirrorless.

ronichas Loc: Long Island

I am a Nikon user and now also have the Sony system. I will be traveling to Africa next year and there is a very strict weight limit.
I have the full frame Sony A7111 with the Sony 100-400 lens plus the Sony 1.4 teleconverter. I recently used this in Costa Rica and was very pleased with the results. I was able to handhold the camera with the lens.
This image was taken at 560 focal length, iso 800 f8, 1/60. Image is cropped.

Architect1776 Loc: In my mind

Yes I know, the only point was they are mirrorless.

jerryc41 Loc: Catskill Mts of NY

wmurnahan Loc: Bloomington IN

And Canon made a mirrorless before 1970, they're called rangefinders. Compact and quiet, yet gave the same or better results than the SLR's of the day, but with limited lens selection. Like 3, a wide 35, normal 50 and tele 135.

Architect1776 Loc: In my mind

Actually they were in the 50's and could use every Leica lens as they were near copies of the Leica rangefinders.
I used a Leitz 13.5 cm f4.5 Hektor screw mount on my Canon rangefinder.
So even though the Canon brand was not broad you could use the complete line of Leica lenses just fine.

joer Loc: Colorado/Illinois

And now some factual data:

Nikon D500...1.89 lbs. Sony...A6500...8.5 oz.

Nikon 80-400...3.45 lbs. Sony 100-400...3.08 lbs.

Nikon D5...3.11 lbs. Sony A9...1.48 lbs.

Nikon D850....2.01 lbs. Sony A7R3...1.45 lbs.

Nikon 400 2.8...8.63 lbs. Sony 400 2.8...6.37 lbs.

Nikon total...19.09 lbs. Sony total...12.91 lbs.

Depending on how you mix and match the difference can be substantial.

That's just one comparison...there are other DSLR/ML match ups showing similar results.

Don't be misled by the fan boys and ignorant.

wmurnahan Loc: Bloomington IN

Why I ended up with a Sony A7ii. Back when I started in photography I was choosing between the Nikkormat EL and the Canon EF, I went with the EF because it worked if the battery died and the EL was just dead. That was what decided it for me, that one point. Both had similar quality and selection of lenses. Both had pro models. But when Canon came out with auto focus, they changed lens mounts and left me hold a lot of expensive glass that a new body wouldn't work with. Being just married and starting a family, my first and only auto focus was a point and shoot with a short zoom made by Pentax. When digital came out, my kids where in college, so again my choice was a point and shoot Panasonic. When I was finally able to get into Digital, I decided on mirrorless so I could use my old glass and wanting FF, Sony was my only choice. Besides I'm mad at Canon, wish I would of gone with the EL, I would be telling a different story and still shooting with Nikon.

So for me the advantages are that I can use legacy/vintage/old glass, and what you see in the EVF is what your picture will look like.

camerapapi Loc: Miami, Fl.

If wildlife photography is on your list of favorite subjects I would stick to a cropped sensor camera. You are wrong, the assortment of lenses for mirrorless bodies is pretty good right now and expanding.
You are right, with good glass no difference in quality between the cropped sensor and mirrorless.

dsmeltz Loc: Philadelphia

There is no weight advantage to achieve similar results when using mirrorless. Lens weight reduction happens when you change sensor size and even then the same advantages and disadvantages that exist with different sensor sizes in DSLRs exist with mirrorless. Right now, mirrorless tech has not caught up to DLSRs for BIF. It will in all likelihood catch up in the next few years, but not now. For BIF you need fast dependable focus acquisition, high FPS and a high keeper rate when you combine the two. The 7D II is probably close to the best you can get right now for BIF. If you can wait a year or so for a solid Canon mirrorless, you should. Their current offering, the EOS R, shows a lot of promise for the future in terms of legacy lens adaptability, native lens quality and accuracy of focus system (including AF to f-11!) But it is not fast enough for BIF. Their next offering will surprise I expect, but even then I would wait a cycle before buying in.

Is there anything the 7D II is failing to give you?

imagemeister Loc: mid east Florida

Yes, right now the only mirrorless suitable for ALL forms of birding and wildlife is the Sony A9 - and you can not afford it or the lenses ! - so the Canon is for you. Some day soon, this may change......the A6500 is close...

..

ole sarg Loc: south florida

the new Leica is still mirrorless! I like to shoot with a rangefinder camera. I use a Sony A6000 and find it more than adequate for my needs. I really could care less about birds in flight. I use legacy glass which costs me very little and focus the camera the old fashioned way in short no auto focus. So I find mirrorless the perfect camera. Of course, those who do not do what I do find DSLRs the perfect camera!
In short, all this is nonsense!

Tomcat5133 Loc: Gladwyne PA

This is a crazy argument. I lost track from my last DSLR's 2 D800s.
I have Sony's now for years. I don't remember but when I look at my imagery on my Sony a7s II I see exactly what I am getting.
I shoot much video now and this is a huge advantage. Not sure about where DSLR's are today.
A lot of folks have big investments in DSLR's I still have some Nikon lens left on the shelf.
And a friend with a studio uses Canon and many lens and i love the gear.
I will admit that Sony menu's are a bit crazy. But the imagery and ability in video is outstanding.
The a7s II with say my 55mm Zeiss lens is crazy good. I believe that their sensor technology
and viewfinders are superb. The a7s (an amazing jump in camera innovation) a6000 I have the
a6300 now and the RX100 series and my RX10 III bridge with 24 600mm lens are great
steps forward. I am sure that other brands I haven't used are very good.
I will be traveling for 2 weeks this friday and no longer worry about a camera weight and fit
for flying. fits in my small backpack of sling light case.
The gentlemen earlier posted link of Ken Rockwell's comparison DSLR/Mirrorless.
He explains the experience much better then I can.