Deepbit does not have any great features that other pools dont, even so, the stats update is one of the worse out there. i mean, 1 hour balance update, wtf. Most of other pools are in real time, or nearly to.
Instant payouts is pointless for me... waiting for confirmed too, why i will ever want instant payout?? thats good for starters only, and after two weeks they lost interest in it too.
The only advantage of deepbit over other pools i see it is the payment methods, they are kind of unique, swepool now has the PPS too, but it is a new pool. Some people dont like the score method, and those are staying in Deepbit, the other mayor pools out there (Slush, BTCGuild and BTCMine) are using score methods, Slush, BTCGuild and BTCMine seen to be better pools for me, i like the stats of Slush and BTCMine, those are much better than Deepbit. BTCmine only lack a way to known how many money im doing per day like Slush.
Addicionally, the fees of Deepbit are excessive at this point.
You whant to known why Deepbit is the bigger pool? because it its the older one, Deepbit was on pair with Slush until 2 months ago, when the total hash rate of the network was ~1.5Thash and dificultty something in the ~90.000, then the Hash rate started to climb like crazy, that was because of the publicity, and the news about "Bitcoins" and "free money with vga cards" started to be posted on forums of all around the planet.
So far ive see about 20 guides on diferent forums around, all of those "Bitcoin starting guides" are writting about using Deepbit to mine, most of them are the same, copy&pasted on another forum...
Thats why Deepbit is the bigger pool.
Personally, i feel both Slush and BTCMine to be better, in all aspects. BTCMine has been having problems with LP lately, but i think is working ok now. Seriusly, i need a good pool with a good averange hash rate, no problems with disconnections (thats why i leaved slush), with good stats and security(i love th BTCMine bitcoin adress lock)... i dont need imposed fees and the useless instant payouts. Bitcoin.lc seems to be good but way too small to join at this point.
This is like "Internet Explorer", there are much better browsers, why it its the most used??? it may have something to do with Windows
Sorry for grammar errors, im from Arg.