Swap a WR250R for a WR450F ?

I started with a 2011 wr250r. couple thousand $ later still was not happy with power. Now have a 2012 wr450f. Couple grand later it is street legal, couple power adders very happy. Thirty mile a day comute is all. She has about 2k on her. Second set of tires. They go about 1500 miles. And yes after a 100 miles or so the seat becomes very unpleasant. But did not buy this bike for komfort. Biggest down side is the larger tank still not quite available. I get about 65 miles on road and 35-40 miles on trail. Thats 1.4-1.5 gallon. So I carry msr bottles for longer rides. 30oz bottle goes about 18-20 miles road and 8-9 miles trail. This all depends on what typle of ride the bike will use alot of fuel if you ride hard.

I was at a dealer yesterday looking at the 450. He pulled out the service manual, and unless I was hallucinating, valve checks were specified at the first 600 miles, and then at 3000 miles......did I read that right? Maybe it was a service table for recreational use and not racing? Anyways, I was happy to see that and as mentioned before, you can easily spend over $1000 on a 250 trying to make it a better dirt bike, or about half that on the 450 making it street legal.....for low-mileage, dirt focused riders, seems like a clear choice, if I read the manual correctly.