Where do I go from here?

[Yorkshire Plodder]

Well, I seem to have come to a major point in my running life! Last night on the Club run I was invited to join the faster group on their long run on Saturday morning. Basically on a Tuesday everyone runs together - well with some of us trailing a little behind! The other days it is split into two groups, basically the 'slow' group and the 'fast' group. I (obviously) run with the slow group, sometimes even struggling to keep up with some of them. It is mostly made up of women who like to run along discussing things like hair appointments and flower arranging type things - not really my scene. Admittedly I do occasionally throw some flowers into a vase and also occasionally head down to the hairdressers, but I don't want to spend my time talking about it. The other group is made up of serious runners and those who one day would like to be (and those who don't want to discuss hair and flower arranging!).
I've now got to make a big decision - should I just stick with what I know and plod round a flat 6 mile route on Saturday or should I head out and attempt to do a hilly 15 miles. What I don't quite understand is why they need to go and start the run elsewhere to specifically include hills when it would be obvious to me that you do your best to avoid them as much as possible!
Anyway, its not raining (for a change) so think I'll head out and do a few miles and consider my future!! I'll let you know what I do after the weekend.