I love running into Lisas online because she's such a rarity. I mostly see higher ranked players use Lisa the most. She is so underrated.
Which I find a bit peculiar because I ran into her all the time in vanilla. I love fighting Lisa offline because it's always an interesting spacing challenge to deal with her. But she can be aggravating as all Hell online, because most PSN Lisa's just throw out the most obvious shit that you could hold while half-asleep offline (KKKK or 6PPP for example), along with a stockpile of OH's that seem pretty much impossible to duck in online lag.
I'll admit that my Lisa knowledge is slightly limited at the moment due to not having faced any non-laggy ones in a while, but when utilized properly, she can be surprisingly effective but I still reckon she's no higher than Mid-tier-ish.
Characters I wouldn't mind seeing more often are: Brad Wong, Bayman, Zack, Bass, Pai, Jacky, Ein, Eliot, Leon, Rachel (to an extent), or LeiFang.
I just wish there could be more character variation. At least on the bright side, the higher your Rank, the less often you encounter Momiji (you just get Helenas instead >.< lol).