What I've found through experimenting with quite a few different girls at parties, some of whom I wouldn't maybe have chosen for a 1-2-1 because they weren't my type physically, is that there are lots of different scenarios that make me cum.
One of these is a shy girl who is maybe a bit inexperienced and seems to lack conversation, but seems quite willing to lie back almost 'dead fish' style gets me cumming in no time. Maybe by being quietly compliant she arouses all my masculine ardour. Of course, any sort of obstructiveness, complete disinterest or discomfort on the girl's part is a complete turn-off, she has to be happy for me to take my pleasure.
Strangely, the GFE with it's conversation and banter can make it more difficult to concentrate on the action, like I've got to keep diverting to find interesting or witty things to say. Nevertheless, dirty talk conversations with everything centred on the action that's taking place always builds arousal for me.
Even more strangely, a girl who I'm very attracted to, like she's exactly my preferred type, seems to put me under pressure to impress which doesn't always make for a successful punt. A girl who is just OK looking often allows me to relax and enjoy the punt more.
Maybe I'm over-analysing!!