I love Party Nut Cups, they look really nice and the cupcakes bake up so nicely in them, no need for a cupcake pan and once you learn how to open them they aren't difficult at all!
I get mine at Cash n' Carry fortunately mine is right next to my Michaels! I buy the 4oz and 3.5, but I prefer the 4, just use a scoop and fill. I think they are overpriced at Michaels, I get a big sleeve of them about 250 for $4-$5, but if that's your only option give them a try. I have never had a sticking problem, ever, so I don't spray them, just line them up on a sheet and bake
I have a great tutorial of sorts that introduced me to them, I can send it to you if you want (won't let me attach here). People around here love when they get cupcakes from me in them. Good luck! Andrea