Mick,
Have you run it on a dyno?

I just saw this thread and was wondering if I'm having the same issues.

I've got a 6AL2 digital on my car and it's definitely having issues.

Rev limiter set at 6500 and it wacks out about 5400.

The power curve drops off but it "tries" to recover.

I'll have to set the rev limiter higher and see how it does.