I 100%'d Galaxy (for the first time) last week. Before this collection I would've said it was my least favorite game of the 3, but now I'm not sure. I think at Galaxy's release I wanted something more open like 64 (which I eventually got with Odyssey), but now that I've had my fill of that I see the more linear experience in a new light. It's so well designed and looks beautiful, and the controls are super tight. The worst levels to me were actually the more open ones that harken back to 64, the beach or bee galaxies. The gimmick galaxies that involve blowing the bubbles or surfing on the rays were kinda lame too but I had a much easier time controlling them on Switch than I did on the Wii.
I started with the Pro Controller but ended up switching to Joy Cons for better pointer controls, and it works so much better than it ever did with Wii Remote + Nunchuck. This is definitely the definitive way to play SMG. Now I have a renewed interest in trying SMG2 (which I've only played the first level of), but I fear that without some of the QOL features of the Switch port it will be harder for me to enjoy. Mapping the spin to a button seems very make or break for me now.