No,nova luncher is a custom luncher it is more smoother than Samsung touchwiz interface.Is your phone rooted?If yes then you can try one power guard just select AI mode and customize it to use conservative CPU scheduler.
I beg to differ here. TW as a launcher is 'the smoothest' out there. But yes, it has its limitations, that's why people like/prefer launchers like Nova, Apex etc. Nova is smooth, no doubt, but TW is smoother. Honestly I haven't seen a launcher as smooth as TW. Next is Nova, yes. If a person can ignore higher desktop grid size, a nice app drawer and several other nifty features then TW is the best for him/her. I personally can't live without a bigger desktop grid (8x6), so TW is a no go for me.
My comment is based on Note 2, so it's based on that phone only.
@Ajay: It's time to change your view mate. Without root you have NO idea how many awesome things you are missing. Don't know why you don't wanna root, though, is it warranty or anything else? It's just a 30 seconds process! Don't we use out Win 7 as Administrator privilege?