The idea for no.1 is a good one; the main focus of the shot (the plane) is spot-on, but you need to try to improve some of the background details in order to flesh the shot out. For example, the horizon would be much improved if it had some bumps and o curves in it, and I feel that in a sky-orientated shot like this, the clouds ought to be prominent - here they are a bit lacking.
Similarly with no.2, you have the main focus of the shot (the cockpit) pretty much perfect, but it is let down by a couple of things in the background, namely the uninteresting ground and sky in the shot.
3 is much more like it. The lighting on the plane is very interesting and you have interesting-to-look-at scenery below you. One pointer; if you're gonna reduce the visibility to the extent that you have, try then not to have clouds in front of the camera, especially here where you have a weird blurry grey-on-grey effectthat just doesn't quite look real.
4 is like 1 and 2; main focus is good, background is bad. Whilst the cockpit you're in is very nicely done, the background is blurry, undefined and basic.
5 is again similar. The plane you have looks fantastic and it is taken from an interesting angle, but again, seriously this time, the background lets it down by simply not being elaborate enough. It needs to have lots of interesting little foibles in it otherwise someone looking at the screenshot becomes bored with it very quickly. Think of it in terms of 'things to look at' in a screenshot - the more there are, the longer a viewer is going to pay attention to a screenshot before feeling they have 'exhausted' the screenshot and there is no longer anything new on it that they can look at. Subsequently they move on.
Hopefully I've helped here; as you've said hese are screenshots from an old rig and these are old shots. Many of your new shots have solved the problems present here.