I think Gametime is only worth using when you have the possibility to auto-import hand histories. Gaming club has the most awful system for hand histories in the business, even when they work, and autoimport from GC is not possible as far as I know.

However, pokertracker in itself is so valuable that there's really no question if you should get it unless your not even half serious about poker.

GT works best with sites that store HH's directly on your harddrive. Like Party and Crypto sites. Systems with HH's by mail also work, but with slower update (5 minutes instead of 1) like Pokerstars.

Sorry about bad mouthing GC, but I just think that place is horrible to play at.