Cash burn heartache and sagging returns has me now using X_DEV (Supercharged AIM) rather than AIM BTB. See below what it can do with a stock like RMBS.
At times it is at 100% cash and at other times is 100% stock (but mostly is in-between like AIM), but it has NEVER gone underwater as you can see by the portfolio value "light-green" line (Right vertical axis) always staying above $10K.
Check out this RMBS return since August01 (Oh baby!):
Those using X_DEV can get over 100%/yr with far less risk than any flavor of classic AIM.