Depending on application, I like them both, but prefer the AVS.
If you are one of those people who are incapable of tuning, and unwilling to learn,
and you just want something to run "perfect" right out of the box,
then you should consider paying the additional money for an AED or Barry Grant built to your specifications.
Remember you can easily buy a Holley that won't run well and is potential trash can fodder if you aren't willing to pay a tuner.
Ever wonder why swap meets are flooded with Holleys???