I must confess it's the kind of question that will get you loads of different answers. So sticking my oar in, Flats are more old school tone compared to the brighter sound of roundwounds. If you like older music or play fretless they are definitely worth trying. I wish I'd taken the plunge about 10yrs before I did!
I know it's been said before but...
[quote name='daniel collin' post='1174003' date='Mar 23 2011, 11:31 PM']just wondering what the main difference is between the flat wound strings to the normal strings[/quote]
Flats are the norm in my World too!