Yep, the version for stopping services without a/c and a bit slower. Sure, why not, I wouldn't buy it myself when we already have the 166 but no reason not to have it. Maybe they could do it as part of a stopping scenario pack, or perhaps as a bundle including one of the much-desired branch lines.
A Class 165 would be better suited to a new route, such as something containing Chiltern Railways. Reason being that the Class 165 doesn't differ greatly from the 166 and wouldn't really offer anything new for Great Western Express. Yep. Polls should be more scientific, i.e. containing reasons for instead of a yes/no answer. You also have to factor in people who don't vote (who presumably aren't interested) which you can roughly gauge by comparing page views against total votes. Also don't allow multiple votes if they contradict one another. (Polls are difficult to get right, but some are just bizarre).
Definitely a missed opportunity even if it only has limited purpose. A GWE twin pack with Class 165 and 180 dmus would add alternative traction on stopping and express services. I would buy this. As for the branch lines for GWE, this is a much more difficult and unlikely addition even if I personally would enjoy it.