I've finally gotten around to upgrading avast from v6 to v7.
In terms of "first impressions", like several people in this thread, I've found the behavior shield "overly chatty" when set to ASK. I had it set to ASK when using v6, and about the only time v6 ever prompted me was when downloading/installing DotNet updates. But now, under v7, it indeed appears very HIPS-like, questioning just about everything I try to do. While in general, I prefer to let avast allow me to decide what to do when a problem is found (i.e., I have ALL its other shields set to ASK), I have reluctantly set the behavior shield back to auto-decide.
Given that this thread has had no entries in about 2 1/2 months, I was wondering what other people were experiencing (or have learned) about how best to set the behavior shield. (If it makes any difference, I'm working under XP/SP3... remaining security per my signature.)