That XR is a great bike if you're mostly riding street & light trails. Major con is It's a heavy bike for the tight stuff & if you drop it a few times on a trail, you'll be wore out. Pros are they'd be better on the highway, plenty of parts & that engine is bulletproof. If you're looking at smaller bikes, you can drop some teeth in the rear sprocket to gain some speed, but you'll lose torque.
You won't find new two stokes for the street unless you're looking at scooters.
Have you considered a Supermoto?