Hearing about Dest/Affliction builds has bone on in my guild a great deal. I Leveled through Demon so easily and quickly. I tried dest in the mid 60's and then i hit 70 and started raiding. For Long drawn out raid battles the best spec ive come up with is a hybrid
http://www.worldofwarcraft.com/info/classes/warlock/talents.html?3500222012235115010002300000000000000000000505000512200010000000
THis spec couples the helpfulness of Dot's with the power of SB spamming. each SB hits for between 2k and 4k. and if you get two crits in a row it is well over 5k. You do lose Unstable affliction DOT which is nice to have but at a 1.5 sec cast vs a 2.5 sec SB that does almost as much dmg i decided to run with the increased crits.... this spec does require a good bit of gear. But is so very effecient i can dps and only have to stop if my threat gets too high.
http://www.worldofwarcraft.com/info/classes/warlock/talents.html?3500222012235115010002300000000000000000000505000512200010000000
THis spec couples the helpfulness of Dot's with the power of SB spamming. each SB hits for between 2k and 4k. and if you get two crits in a row it is well over 5k. You do lose Unstable affliction DOT which is nice to have but at a 1.5 sec cast vs a 2.5 sec SB that does almost as much dmg i decided to run with the increased crits.... this spec does require a good bit of gear. But is so very effecient i can dps and only have to stop if my threat gets too high.