Just picked up a 2006 BV250 (a seemingly rare model year for this scoot, pre-EFI, too), and haven't been too impressed with the rear rack - it looks nice, but it's all-plastic. I noticed that the Beverly Cruisers use the exact same frame, but feature an updated tubular rack - comparison of both designs here:
^The BV250 Rear Rack (USA & Tourer models)
^The Beverly 250 Cruiser Rear Rack
It's hard to tell whether the mounts on each side are metal or plastic, but I hope that, either way, it will be a stronger supporting mechanism for a top case, and also the occasional event when I strap a 40-lb backpack behind me for a wilderness backpacking trip.
I searched long and hard, but haven't seen anyone making this swap, but I finally found a Cruiser rack for sale in Italy at a somewhat reasonable price on ebay ($45 + $45 shipping to USA), so I'm going to give it a shot.
The other great benefit of this mod will be greater options for top cases, as the Givi Monokey premium cases do not provide a mounting option for the BV250 (Touring) models, but are compatible with the Cruiser luggage rack. This fact implicitly confirms my belief that the Cruiser tail rack is stronger, but the proof is in the pudding. Despite the new-found Givi offerings, I'm going with a Shad SH-40 Cargo case, as I like the design better than the Givi options.
I'll update as my new loot arrives.