Twitter is Twitter, seems fine and performs well enough, but it's not going to win any awards for any awesome features. Can't say I've ever texted more than 10 people at once - though the limit on the stock messager is 10 here. I'm not using any of the Samsung stuff yet - most of it seems pointless to me, especially the various stores and hubs - though I'll probably sign up to activate the stolen phone finder thingy.
I can't imagine it's a huge difference from a Note 1 - though you could make it entirely unrecognisable to my device by rooting and flashing, such is the fun of Android. Switching to iOS from Android would probably make me want to shoot myself