I agree with a previous comment, that the pictures look like they were processed with an HDR app. I have Photomatix and my shots come out very similar. Did you use a tripod? We are going on a similar trip that starts in the Swiss Alps,moves on to the Rhine river at Basel and cruises down to Amsterdam. It's an alumni group trip with a professor and local guides and I know from previous trips that there isn't much time to set up a tripod. Anybody has any ideas to offer to solve this dilemma?

I bought the Nikon D3400 with the Nikkor 18 - 55 mm lens for my then 12 year old granddaughter, she is now 13. She has been able to use the camera and create very nice photos. I don't think she uses all the features this camera offers, but is a very good platform for learning. This morning, 5/6/18, I had an email advertisement from B&H Photo that the D3400 with the above lens is on sale for $400. I think that's a pretty good value.
Otherwise, I gave my Nikon D5200 with a couple of DX lenses to my oldest granddaughter when she was 16 (she is now a freshman in college) and she took it to Iceland on a Spring Brake trip and came back with super pictures.

When I retired five years ago I was facing the same dilemma. I bought a Nikon D3200, which I traded in for a Nikon D5200, which I then traded in for the (at the time) new D5500. These are all crop sensor cameras and I was not as happy with my photos as I wanted to be. Then I took the big leap, sold the D5500 and bought a full frame camera, the Nikon D750. I will stay with this camera for a long time. So save yourself the agony and expense of constantly upgrading and go straight to a full frame, or FX camera. By the way, the AF-S NIKKOR 24 - 120mm 1:4 G ED lens is a good choice for a first lens. Its maximum aperture is f/4 for all focal lengths and the pictures are real sharp. You can also get a great bokeh at the f/4 setting for all the focal lengths.

I have the Tamron 150 - 600 telephoto, which I like very much even though it is very heavy. It's definitely not a "walk around" lens and I only use it when I really need to pull in something far away. I also have the Nikon 28 - 300, which I have been using as an all purpose lens; however, I just bought a Blackrapid camera strap and even the 28 - 300 is a little cumbersome, not the weight, but the size. This only matters when I am in a city like New York where people are always bumping into you. In less crowded spaces the strap and the 28 - 300 lens work really well together.