With what's been said i'd say it sounds like a good idea to have both profile pages...
What i'd like to see (and would allow the use of both pages) is all user related info (minus threads) under the BuddyPress profile pages, and all thread tracking under the old profile pages.
Then draw your attention to simply removing the unwanted (user info) from the bbPress profiles (you could give the page a related heading - eg. Forum activity for "Username") and focus on improving / re-writing the threads query that looks up posts relating to the given user.
[user info, website, name, etc...]
Essentially split the roles and let the bbPress side of things do all the thread tracking. Admittedly bbPress is the area where the thread tracking is lacking.. and requires the work..
Doing all this under one page is just going to increase the amount of queries overall for the site. If you split the queries/roles between 2 diferent pages you've already cut down total queries and frenquency of queries per page view... Thread tracking would(in my mind) be the bulk of the biggest queries on the page anyway..
I think it would be nice to have both profile pages work in unison with one another, rather then choosing one over the other and having piles of information in one place...