Horses for courses, of course.
On the wet side of WA and OR, on our tight or slow-to-mid speed steeper flowy trails, the 200XC-W was regarded as king by many riders (who like KTM). The TPI 150XC-W seems to hold that crown now.
The exceptions seem to be larger/heavier riders, riders who want to lug a bike and not rev it out, riders who want to head east or south to drier areas and ride faster terrain - all three of those groups tend to get a 250 or 300. And the riders who want to play on MX tracks get an XC model.
I'm 155-160lb in my birthday suit, am going to keep my speeds moderate at most, and want to play on technical trails. I like light chassis bikes. I'm going to gear the bike down a bit with a 52t rear sprocket to get 1st a little lower and I don't care about the loss of top speed in 6th because there's nowhere around here to safely top the bike out anyway. I think this one will be good for me.