3. Members spend:
          ALL current DKP on any on-spec items.
So... those that could use the gear to be more effective in raids have to pay more DKP??? I would make those that need the piece for personal gain and not raiding (farming gold) pay more for pieces over those that are geting the piece to help the guild in raids.
What system do you use? and does it work well
Our guild basically uses a Zero Sum DKP with a few tweeks.
We give dkp for:
1. Being on-time and ready (pots reagents ect.)
2. Being on stand-by (in case some one has to go, which happens offten)
3. Downing a boss (including those on stand-by)
4. Being there from start to finish (including those that were on stand by)
5. And a dividend of the set price from epic gear that drops
We give the piece out if:
1. The piece is for your class and spec
2. Mains over Alts
3. You have the highest DKP of all that bid
4. and you have a 33% attendance
We never shard a piece that someone needs even if they don't meet one of the above requirements.
The way we charge for gear is a set price for each piece. Our original DKP system was NDKP (nurfed DKP) and we figured out how each stat effected the price and now we set our own prices for the most part. When a piece drops, the DKP price is split between all the raiders including the person who got the piece. So if piece in KZ drops thats worth 20.70 DKP we split the dkp equally between all 10 raiders.
The only concerns we have heard of are with newer guildies thinking they can't get gear because long standing guildies have 100+ DKP. But our perspective is that we are getting tired of new guildies coming on runs for a couple weeks and raking in gear and then leaving. This system makes them get involved in the guild and hopefull stay and help the guild out, once we get them their gear. But like right now we are moving towards wraping up KZ and a new guildie can come on a run and get, in some case, 4 and 5  pieces in a single night, and we don't realy need the void crystals so they get tons of gear, negating the complaint.