I see what you mean. SC4's online wasn't terrible good especially compared to SC5's which is far superior in that respect as well as customization. But in depth I still think Sc4 in better Imo.
I tried playing SCII, everything was too safe.
SCIII, too glitchy & horrible balance.
SCIV, bad online & top characters are too safe.
SCV, I hate it when Mitsurugi can kill me in 4 hits.