As someone who'd only played SM64 sporadically in the past, I actually had a lot of fun with it, despite constantly fighting with the camera. I was honestly surprised by how easy it felt, I had very little difficulty getting 70 stars to clear it, I suspect many of the last 50 would prove more challenging, but I don't really have any great desire to go find them.
I have played Sunshine quite a few times, however, and while I still love it, I was really surprised by just how hard it is. The camera isn't as bad as 64's, but it's still a pain, and the movement seems to have the opposite problem as 64, Mario is super jerky and has a really hard time staying on short platforms, which is not something I remember from the Gamecube version. Beyond that, some of the platforming sections are just genuinely really hard, and unlike 64, you can't just skip the hard Shines, because the 50 you need to beat the game are fixed, which is probably not an ideal design. I haven't really had any of the collision issues or other bugs people complain about, the game is just hard.
I know I played through Galaxy on the Wii, but I honestly don't remember very much about it, and I've only scratched the surface of it on the collection, I probably won't go to much deeper until I finish Sunshine, but it definitely looks great in 1080p, and controls nicely with the pro controller, though the motion aspect takes some getting used to.