The original W650 was a poor seller although a good used one will run you close to what it cost new due to the rareness now. I personally really liked the W650. The W800 looked great in the original green/silver with chrome and metal engine instead of blacked out. There were a few other colours over the years that looked great too. Its a fun, standard motorcycle. It isn't going to be fast, or handle great or cross the continent in luxury. It is just meant to be a pleasant, neutral riding bike that does a lot of things good but nothing exceptional. There used to be plenty of these before bikes got so specialized.
As for buying a Triumph, that's a no go for me. I'm a Japanese bike guy. Always have, always will be. The only place to get parts for the Triumph is an hour away from me and I'm not much of a mechanic beyond the basic stuff, so I don't want to have to deal with taking it to a Triumph shop. I want a bike that every shop around can get parts for and repair easily. I know a few shops that aren't dealerships that can't seem to even order Triumph parts directly. They have to order them from GP, pay full retail and then either make no markup on the parts or pass the cost on to the customer which usually scares them off to the dealership. I really love the old style but not the exclusivity of a Euro bike.
C'est la vie. If I ever get the time and money to have two bikes maybe I'll search out a nice used W650 and have fun kicking it!