While I'd really like a bigger tank I actually like the steel tank. I can throw my old Nelson-Rigg magnetic bag on it and it sticks even when it shouldn't offroad. I won't be able to do that with a plastic tank.
Instead I'd like a Rotopax capable rear rack. Something with the option to include some panniers/side bag supports.
On road, and it really is to early to tell, I'm getting about 175km to a tank, off road, and this is the amazing part, about 150 -160. Adding an extra gallon to that will get me down the road an extra 100km+
My fuelly account for my CRFL: http://www.fuelly.com/driver/bungie/crf250l
The annual season wind down is nearing. Maybe I'll get energetic and build my own.