Silverman Loc: Michigan

Also check the Altura AP-N1001speedlite unit, $59.99 on Amazon.

Clapperboard

DaveT I shoot with Canon but I am pretty sure the same can be applied on Nikon.
I set the built in flash to activate the off camera flash (slave unit) but have no effect on the exposure.
Thus the on camera flash only controls the slave.
Another useful setting for the on camera flash, built in or attached is to set the 'preflash' to on but the flash to off. That is the preflash the ETTL or ITTL (Nikon) facility would use to establish the relative flash output is on so that the preflash is actually used to assist focusing in poor light but there is no flash output to interfere with exposure when you don't want flash.

billnikon Loc: Pennsylvania/Ohio/Florida/Maui/Oregon/Vermont

You can get a mint used Nikon SB-800 from ebay at a good price, these units are dependable, accurate, and made to get the most out of your Nikon camera.
That said, this flash you are looking at looks like a good deal. But, keep in mind the following limiting factors, if they are not a deal breaker for you, I would say go for this flash.
Now here is what it won't do. No High-Speed HHS synch, no CLS commander/master mode (even though the manual says clearly the mode is included and describes how to use it! Weird!). I tried using the flash off-camera with a Nikon SC-17 cord (which works with the Nikon SB-910) and the 750 II strobe acted as if it was not connected to the camera. That is, it would not fire at all. Bummer.
Another fault is that there is no way to turn off the sleep mode which comes on after 3 minutes, so using it with a radio trigger off camera might be a pain if the strobe keeps turning off, if your trigger has a wake trigger mode it might work out.

Another weird quirk the Meike strobes have is that the flash ready light in the viewfinder will stay lit even though the strobe is recycling. That is the flash is telling the camera that it is ready to shoot when it really isn't. I have a Meike MK910 (perfect clone of the SB-910) and it does the same thing.
If you are looking for a decent strobe for on-camera use such as event work or longer lens use (think 70-200mm body as opposed to your wide angle body) than this is hard to pass up at $55 each. With a metal hotshoe the electronics inside will fail before the physical body will. Even if it fails after a year or so you are still ahead. I might buy an extra one, it's cheaper than what the Vivitar 283 used to cost!
To recap, if this was priced at $100 I'd say in the current marketplace to pass on this strobe, but for $55? Sounds like a deal to me if you can live with the limitations I mentioned.

UPDATE: 9-27-2014: I went ahead and bought another one I like it so much. I have tested it with the excellent Yongnuo RF-603 II wireless flash triggers (for Nikon) and the 603's "wake-up" the 750 MKII every time from sleep mode. This means you can use this little sucker off-camera with a softbox/umbrella on top of a lightstand and with the port for an external battery pack you can really go to town.

jccash Loc: Longwood, Florida

I don't use a flash often but bought the little Nikon SB-300 to use with my D500. It works great for my use.
Nikon SB-300 AF Speedlight Flash for Nikon Digital SLR Cameras https://www.amazon.com/dp/B00ECGXAA0/ref=cm_sw_r_cp_api_JcDDzbWVWPBBY

When using your camera if you can't figure out how to turn it off just hold it down as your taking a picture. Sounds like you are in full automatic. Next to your green automatic setting there is an optional setting m: full automatic no flash.

EnglishBrenda Loc: Kent, England

I also endorse Yongnuo products. Which one to buy depends on your requirements.

mas24 Loc: Southern CA

As already mentioned, I would go Yongnuo #685. It is your best bang for the bucks.

ronz Loc: Florida

Before you buy I suggest you look at Phottix. I have several and have had them for eight years and never a failure on camera or off. They have a HSS and you can set three channels to different powers. Very simple to use and I have had them on outside of a house and the trigger works great up to 100 ft. May be the best on market if you are looking for longevity.

jay levine

allan , i've got one , problem is the manual is poorly written and in bad english so its hard to make work not intuitive in the least however it is almost a copy of the canon , so if u can get a copy of the ops manual u may be able to figure it out

MidnightManiac

I shoot Canon but pretty sure the same applies for Nikon. Yongnuo is a great quality flash. Bought a pair of Yongnuo (speedlights) YN685's. Have a YN622(C)-TX Wireless Controller I use for off camera flash. These work equally well on my T5I, 5D and 7D mark II. The quality is as good as my Canon speedlight. The cost for this setup is less than the cost of one Canon Speedlight. ETTL to me is a must. Research your options that will best fit your needs. Yongnuo has become my flash of choice.

kb6kgx Loc: Simi Valley, CA

The price on the Altura seems almost too good to pass up, but I just have a natural hesitation about something priced so low. On one hand, if it does what I want it to do, than $59 isn’t bad. Or, better to spend twice that for the Yongnuo, which is STILL a great deal when compared to the Nikon brand, and even half the price of the Nissin.

Don’t mean to interrupt the original poster’s question and discussion, here, but many of you have said “it depends on your needs” or whether or not you want on-camera or off-camera flash.

For me, it’s all (well, mostly) about power. I’ve been using my trusty Sunpak 555 handle-mount for a very long time. GN of 150, it will light something up that is a good distance away. But it won’t work in auto mode with today’s bodies and certainly no TTL. I’m thinking that, for the price, the Yongnuo comes closest. I have NO need for wireless control or multiple flash units. I want to do two things: 1) light something up way out there and 2) something that works in auto for everything else.

Boris Ekner Loc: From Sweden, living in Guatemala

At first I bought a Neewer NW561 (eBay $36) but found it too much of a manual flash than I appreciated. (It only has one connector to the hot shoe of the camera.) It's not a bad flash, not at all. But I wanted one that I could control by the camera settings.

So I bought a second one, a Neewer NW982II iTTL (eBay $36) From the top of my head this one has 5 connectors to the hot shoe witch means that the amount of light as well as the flash zoom is controlled by the camera. Exactly what I was looking for from the very beginning. I find that this flash fits my needs far better than the first one, witch I will use as a slave when-/if- ever I need one.

dennis2146 Loc: Eastern Idaho

I may have missed it but I do not see your Nikon D3400 listed in the acceptable cameras list.

Dennis

sirlensalot Loc: Arizona

I looked at this one and decided against it based not so much on reviews, but I wanted E-TTL and HSS with a guide number higher than my 430 EXII (Canon) Bought the Yongnuo 568 EX II for $92.
So far so good. I am satisfied with my choice. They make the same flash for Nikon.

GoofyNewfie Loc: Kansas City

Probably just haven't updated the advertisement.
Betcha it fits.

dennis2146 Loc: Eastern Idaho

It probably does but I would be calling the selling company to make sure.

Dennis