I actually had very frustrating experience with Revell R8 (I believe I posted a thread long time ago). After building the entire thing, I was ready to put the fully body on top of the finished body. Guess what? It doesn't fit! The wheel arches are too wide compared to the body arch so there was no way I could fit that in. I ended up sanding both wheel arches to try to make that fit but it ended up messing up the whole body. Honestly, I have no idea how that happened since none of users on this forum seem to had that kind of issues.
Then, I was working on Revel Enzo, which I couldn't finish.
I don't think resin kits are easier but I felt that it's going to be a lot more flexible since there's good amount of sanding to do. Gundam kits that I am looking at are from Bandai (well known). For all car kits, I think Tamiya is superior over Revell IMO (I built 2 Tamiya and Bandai and Tamiya cars went pretty well besides the decal part. I bought a wrong decal solution and ended up ruining decals
)