Palladero,
I'm in the same boat as you, 5'11", 235. I also just got back into riding after being out for 13 years. (I got tired of watching my 12 year old son ride by himself) The last bike I had was a 1987CR250, sold in 1990. It was stock and handled the woods great.
Last month, I purchased a 1993 RM250. The price was right at $750. Since it is used, I don't know the history. I did rebuild the top end and install Boysen Pro-Series Carbon Fiber/Fiberglass Reed valve in the stock reed cage. The bike came with a Procircuit Platinum Pipe and a 304 Silencer. I use it primarily in the woods.
I think 2 stroke motocross bikes are great in the woods. If you like the "snap" of them, nothing can fill that thrill. In my opinion.
I don't know if your buying new or used, but heres my take on the bike. Handling is great, easy to whip around. The bike feels nimble and light. Power is great as well. Almost all situations can be handled with a twist of the throttle. Very little fanning of the clutch is needed. The bike does like to keep the momentum up, only for the steepest of climbs.
To give you and honest opinion, I'm nitt-picking the bike some. It works great for me. Power is great and predictable. Long/Steep climbs aren't a problem and can be tackled with minor clutch fanning. The only improvement I'd make would be gearing. I would drop one tooth off the front sprocket only for really tight woods. I have an O-ring chain, it shows no need of replacing any time soon. But for around $15 dollars, it seems the most cost effective mod for torque.
Hope this helps, Steve.
P.S. I don't plan on ordering a front sprocket anytime soon.