Only really play micro (2 and 5nl) so by no means an expert, but you are right that Stars is pretty grim/very nitty in my view. I find both 2 and 5nl a real grind. (Especially in Zoom)
Skypoker is better in my opinion, you get a good mix of of tough players mixed in with people “investing” gambling winnings so worth giving it a go and just being selective on who you get fancy with.
Done a few MTTs on Party Poker that have seemed very soft but not got enough of a sample size to give you a firm view.