Well, I've just purchased a Dahon Curve and am quite satisfied with my decision. =D I visited some stores and test rode a few folders and I must say I was very impressed with them in general. My favourite was probably the Brompton - it's just such a comfortable ride in such a neat little package. Unfortunately, you guys were very right about me underestimating the bulk and weight of the average folder. =D The only one I could easily lift was the Curve, however I really liked the way the Brompton could be rolled when folded - it's somewhat awkward to roll the folded Curve.
I was very tempted to purchase the Brompton, however I couldn't convince myself it was worth more than three times the price of the cute little Dahon. I find the Curve more difficult to power and it's certainly a twitchy little thing, but it's light and, while not very comfortable, not exactly a pain to ride either. Hopefully, a change in saddle will make the ride more cushy. I can't wait to pick it up from the shop and take it for a spin. =D Thanks for everyone's help, the advice and guidance was (is!) very much appreciated! =D