Tennistomcat we have similar experiences it sounds like.
The regular pure drive is just too light and the SW is too low. The plus gives you more leverage and boom. I add lead at 12 and that's all I needed to do.
Only reason I made this thread is because I feel like a lot of people may not know how great a plus length can be..especially when it comes to a pure drive or APDC.
Please help TT Member BruceD get a wheelchair so he can play tennis again - http://tt.tennis-warehouse.com/showthread.php?t=496820