I let my Coby sit last night with Softlocker activated (no sleep). This morning after about 12 hours sitting I had 40% battery left. So my thinking is if you dont mind charging it every night this will be fine. If you plan to not use it for a while (day or so) power it down. So it becomes a lessor of evils. Be annoyed by screen wake ups or know that you need to charge it every night. Which as a rule I do anyway with my phone and iPad.
Well last night I turned off Softlocker and let the Coby sit for the night. It used considerable less power. This morning had 75% left on the battery. So clearly not letting the unit sleep draws more power. I installed JuiceDefender and will see what it does. But at this juncture having Softlocker to kill the screen displays and an easy ability to turn it off when I want longer battery in standby is not bad. The benefit of having the Market far outweigh the disadvantages.