Terrain is more or less the same let's get clear on that, I have FC2 and yes it's nice polished LockOn but that's it, however the terrain and overall graphics are unreasonably demanding, my terrain benchmark to this day is il2 with amazing details, solid complexity and runs smooth as butter even on ancient machines. LOMAC never had that you always needed top notch state of the art computer to run that game.
So basically it's the same old flyables on a same old terrain, sure nice, polished and updated but content-wise it offers nothing new unless you are an on-line type of player and on top of that modding is almost discouraged instead encouraged.
Mind you I'm not saying LOMAC is a bad product, quite the contrary but I find all this praise waay to much
Maybe they are but like I said they are also much more demanding, I would even say unreasonably demanding so they ask for way more $$$ than what's on the pricetag...
As for Nevada it's a training terrain, for 20$ I think that's too much but I understand the fan-base wanting it no matter what...