If you're hoping for a bike that's an equal to an off-road-only race bike, not likely.
The WR-250R weighs a fair bit more, makes less power, and has trail-riding suspension, not trail-racing suspension.
Money and mods will make it better, but myself, I'd still view it as a kick-ass dual-purpose bike.
If you'd be satisfied with a bike that's not too bad for a dual-purpose bike, that's probably more like it. :)