First off, you will not win any points for looking good or get any admiring glances from onlookers by wearing these, unless they too are converts to the Vibram FiveFingers.
I've been using these for running for a couple of months now and after the initial calf problems I caused myself by starting at too high a distance, I now love these trainers. My legs feel so much stronger and more stable for using these which is the major plus for me, as I have knee problems and kept rolling my ankle every time I went running, even wearing stability trainers. I haven't rolled my ankle once with these. The treksport are one of the thicker soled shoes in their range but having delicate baby feet these suit me perfect for running on concrete and parkland. I haven't done any cross-country in them yet but see no reason why not.
On the negative side other than the fashion fail, they sometimes feel a little slippy on some types of wet concrete and are super expensive, but for me are definitely worth the price.
If you're just starting, I would seriously recommend only running a third of your usual distance max until your muscles can cope with the extra work, but it'll be worth it.