I bought a AA TDR on the rebound and hated the thing. Buttstock was fiddly to attach, allen key required to fit the moderator onto the pencil-thin barrel, by which time the thing was horribly long, skinny and straight like a broomstick. If you don't need it to 'take down', in my opinion it's much more horrible, expensive and with a lower shot-count, than a standard S410.
The MK1 Vermy was crap in different ways... very accurate, but always leaking air... the fairly pointless tiny front cylinder is connected to the big buttstock cylinder by a fragile steampunk arrangement of copper pipes. The bottle stock is tricky to attach, and contains o rings that are virtually impossible to see, never mind replace. Removing the butt releases all the air from the front cylinder and pipes in an alarming manner that likely damages the impossible o rings. Although the Vermy is sold as a TDR, many owners recommend keeping it in one piece for those reasons. If it don't leak - don't disturb it! Also the cocking action didn't feel very robust, and when uncocked, something in there rattles back & forth like a loose spring...