I have almost no reason to ever sell my BB2's for anything else but, if anything tempts me, it's the handles on the BB3's.I think the BB3 addressed your observation #1 concern with the updated handle. I wouldn't mind a side handle on my Two10s to carry it long ways sometimes.
I do at times miss that bass, best playing Fender P I've ever owned but the neck was a little too chunky for me. I actually matched the Two10s blue baffle to that bass. Luckily I have other blue basses.
You also have a great eye. That is a One10s sitting there. After a break that day I switched out the BB2 for the One10 to try together but forgot to take a pic. It definitely added something to it but I liked the BB2 and Two10s for the added volume and bottom end. I actually plan on using the 3x10 setup in November for a medium sized bar that I won't have PA support. I really like the height to bring my sound closer to my ears.
I also have a One10 and have considered adding a Two10 to do what you described. Would love to hear your impressions after that gig.
