I'm on an 07 RM. I've had a couple CRF 450's prior to this. I'm 6', 180 and the bike is fine. I'm still trying to get used to shifting again, but other than that, it's fun. Since you're already riding a 2 stroke, and a KTM at that, you shouldn't have any complaints.
My opinion of the power, with a PC works pipe and shorty, stock gearing, is that it has very strong low, mid and it's decent on top. It feels like it signs off a bit earlier than I thought it would, but like I said, I 'm coming off a 4 stroke, and a great one at that. I'm thinking of adding a tooth to the front to try and keep me from having to shift so soon out of corners.
The suspension is good. At first it was very harsh, and I was going to send it somewhere to get done, but after a handfull of rides, I was able to get it working VERY well. The forks work well on big hits, no headshake and it goes straight as an arrow.
My only problem right now, is getting used to using the power to turn. I forgot how much you have to use the back tire to turn with 2 strokes.
That price is great too. I paid 5 for mine over the winter. Good luck finding a 4 stroke that cheap, or even a KTM 2 stroke.