Ok, since we're not done beating this horse yet....
I don't disagree with anything that has been said about the 300. It's a fantastic bike, smooth power and really easy to ride. Can't go wrong with purchasing one, whether you're a novice or an expert. Like rrocket said, you can just put it in third gear, leave it there all day, and twist the throttle as desired.
And yes, it's light - way lighter than Bob's current CRF, and basically the same weight as the 250 and within a couple pounds of the Beta 200RR.
But, even though all these bikes are physically within a few pounds of each other, they're all going to feel different. Whether it's the extra moving mass of the engine, or just the extra power, the 300 is going to feel like a heavier bike. I think ktm called the 250 "high strung," but I'd say it just has a peppier feel. Mine has a few mods that give it tons of low end power, but it still probably revs a bit faster and feels a little more eager than a 300. (And my 2011 has the map switch for the ECU as well. Don't need to pay extra for the Six-Days version - you can buy the handlebar switch for $30 and install it yourself.)
Like Bob said, that Beta 200RR is known for its friendly, smooth power delivery. Even though it weighs about the same as the KTM 250/300, I think it's going to have a much different (lighter) feel, and maybe not tire you out as much over a long day. And then of course there's the KTM 150 - 201 pounds! There's really something to be said for that "mountain bike with a motor" kind of riding experience. For Bob, living back east (no huge, loose hillclimbs, I assume?) and being a fairly light rider, I'd be leaning more to the 150/200 side of the equation than 250/300.
For a flawed car analogy, I'd say the KTM 150 is like a Lotus Elise, Beta 200RR like a Porsche Cayman GTS, KTM 300 is like a Porsche 911 Turbo. Not sure if the KTM 250 is like a Cayman GT4 or 911 GTS.
Regardless, the point is that they're all awesome cars (bikes,) but do have noticeably different character. Too bad about the demo days, because it would be really helpful to throw a leg over each.