Personally I like getting a technical T-shirt after the event. But being female and not very large they so rarely fit me. The only ones which I have that fit are from Edinburgh Marathon and The Grizzly. I've stopped taking them at my local running events in Bristol as they are like tents. If gender specific T-shirts are difficult to organise then having an extra small option will mean that people can wear them and provide advertising for your event for future years
I'm running in the Welsh Castles Relay this weekend. It will be my third year and I am always worried about coming last. I run for a business team and we are lucky just to get 20 runners whereas the running clubs which make up the majority of the participants have try outs and strict cut off times. It attracts some top class athletes, of which I am definitely not one!
I don't know why I worry as my team would just be happy that I ran and the support on this event is always great so you know people would be still cheering for you.