Okay I figured out the Betta situation. I was confused on their product line. It's actually kind of confusing, but it looks like the products are:
betta (not sure this exists in the wild at all)
betta 2
betta se
betta se+
I have the SE. the SE+ appears to be the most recent model, the one with the salt tolerant motors and external charging capability. I'm not running salt, but the design of the salt tolerant motors would be appreciated. Oh well, I'm gonna happily live with what I got. Actually my pool is entirely spotless so far, so I guess so far you can call me a satisfied customer.
Betta folks need to come up with a more coherent product terminology, however.