I've never been to LA Triumph - too far away, I guess. I've been to the dealers in Lomita and Brea.
The dealer in Lomita is the infamous Matt Capri (land speed records at Bonneville on Triumphs, factory funding, etc). That said, he's more of an old school twin guy. If you're into Bonnies, Scramblers, and Thruxtons, that's the dealer you want. He is also the only US dealer for the new Norton and also sells Royal Enfield.
The dealer in Brea sells Ducati and Victory motorcycles as well. This dealer is more "in tune" with the modern motorcycle and would be my service choice for the Street Triple. So far, I haven't needed any dealer service. I can handle oil changes.
As far as getting deals is concerned, I haven't seen any of the local dealers that like to wheel and deal on accessories and stuff. When I bought my Triple, I called around and most dealers just started with MSRP, added setup, tax and license and quoted that price. Pretty disappointing, really. I ended up buying the bike from the Lomita dealer for US$1K less than anyone else quoted.