Why mine at any other pool when Eligius is 0% Fees?
Downtime.
I guess you could do elig + a backup pool.
Not sure I've experienced any downtime in the past month or so that was caused by eligius.
And please tell me, why do you mine at Eligius? Such an ugly site! That Wizkid and his pool.
I mine at eligius because with 11 Jupiters, 3% Fees would have been over 11 Coins already for me that I would have given to BTCGuild or other pools.
Why mine at any other pool when Eligius is 0% Fees? Because you like pretty Stats? Not worth all that lost money.
Also 105% PPS NMC helps out, get an extra coin or two per month. Pool basically pays you to mine there
Ghash.io has 0% fee, pays transactions to miners, and merge-mines NMC, IXC, and DVC - and their stats page seems to be very reliable.
Ghash.io has made it extremely clear that their fee is "currently" 0% and could likely change it in the future. They are directly connected to CEX.io and have the majority of the networks hashrate currently.
Unless Eligius gets too big I don't plan on switching and would sway others from joining a pool that currently has 24% of the network https://blockchain.info/pools?timespan=24hrs
When I started mining on Eligius two months ago, it had 2% of the network hashpower, and 50BTC had ~20%. When I quit mining there yesterday, Eligius was at ~15% of the network, and 50BTC was almost nonexistent. These things change frequently and quickly.
If you are really that concerned about decentralization for the long-term, set up a P2pool node. Anything else is just a very short-term strategy that ultimately will not be sufficient. The majority of miners will always tend to mine on the pool where they perceive the most profitability, just like they do currently.
Help make P2pool (or another distributed pool that you invent) the obvious pool of choice, or continue to watch miners flock to the biggest pool with lowest fees, the most merge-mining, or some other perceived advantage.