And don't forget that one of the evolved versions of her skill gives it a really short recharge time if she kills the target
As for characters I don't use, I don't like Jack much, mostly because of her personality. And with my current playthrough being a female Sheppard, I'm glad I decided to go the Sam Carter route on this combined playthrough (went as far down the Kaiden romance as I could before Virmire and killed him off, and planning on doing the same with Jacob and intentionally killing him in the suicide mission). His dialog in the romance is just so over the top.
The femshep and Jacob "romance" looks and sounds more like workplace sexual harassment than anything else. Some of the lines in the Miranda one are pretty bad to from what I've seen, and it's the path you need to take to earn yourself a gander at this...
The only romance plot I actually did was Jack's, but I want to do the Samara one with my Renegade shep so I can use the ending as his excuse for being a prick in ME 3.