The WR250R is the best do it all bike available. I used to ride mine 60km to work and back every day then on the weekend take long 300km trips into the forest then return to start riding to work again with just an airfilter clean.
It's not a slow bike either:
I did find it very weak in the sand but riding in sand is shit anyway. Used to ride in the mountains with Husky 610's, KTM640s, XR650R's then in the forest with 2 strokes, whatever it could do it all. The 610 gave it a bit of a run for it's money but then the engine blew up?! Is that what you call an adventure? I just see a big credit card bill. See it happen with KTM's all the time too. If you're not racing and you just like to explore off-road then there's no doubt in my mind which bike you should purchase. You don't even have to open the engine until 42,000kms should this be overlooked? By the time your friends are done servicing their bikes you'll be at your destination already. Also you don't need to buy a 4WD with a trailer to take it everywhere which is a HUGE timesaver, unlike the 450s where you have to rebuild the engine every however many hours making it a bad idea to run up those hours getting to the trails. Wake up at 8am, be in the forest by 10am. It used to take me 2 hours just to prepare my fuel, tools etc and load my old RM250 onto the trailer but with the WR250R sometimes I'd be on my way home already.
Oh and you'll burn half the fuel the other bikes do too. And never have I ever had any problems at all getting up hills... not sure why people assume this before riding it. It's designed with this in mind by having the 2 first gears very short so it can go up anything...
There are other vids on youtube with people doing huge jumps on them on the MX track (not really my thing but if it floats your boat...)
Again if you're racing or want to beat your chest as you gain a 10 second lead on your mate then there are much better bikes you can buy, but if you're looking to explore then get the WR250R.