My (perhaps limited) knowledge is that mining in a pool will give you more consistent payouts, as you've got the power of the pool behind you.  With solo mining, it's a crap shoot.  You could get a block on your own in minutes (so very unlikely) or months, if ever.  I decided to join a pool to build up a coin-base.  If I ever had super high gh/s, perhaps solo, but I just don't think it's worth it to me.