BE inventory on the new tool is a small subset of flights that will actually work for a BE redemption.
As part of a round trip, I used the regular mileage redemption search tool looking for a business saver itinerary. The one I wanted had a short segment that had no business availability, was in coach, the rest was all in business. The itinerary was one of 20 or so choices on the regular award booking engine at aa.com, while the new businessextra.com booking engine did NOT offer that itinerary. It showed only about 3 choices (vs 20 regular mileage redemption itineraries for business saver).

So I put it on hold and called to see if business extra/meetings services would allow me to book it with a business saver BX1B for a free round trip business class domestic flight. The agent I spoke with said you couldn't mix itineraries and it would require TWO certificates. I pointed out it was a voluntary downgrade for 1 segment, so she "checked with reference" and came back and said oops you're right, and she booked it for me. So while the new site offers to book flights using BE points, there are a lot of other itineraries that you could be overlooking. I have yet to see any double connecting flights when itineraries are available for single connecting flights. (But they will be shows on the regular mileage booking site).

One thing I DO like about the new BE award flight search tool s the ability to filter in or out specific connecting cities. IE avoid Charlotte, or whatever.