Depends on what you are going to do with it.
Playing around in the neighborhood or messing around on some trails, the Sur-Ron is capable, and it is a hoot to ride. But I don't think I'd commute on it farther than a few miles. It can hit 50mph, but it's a little on the twitchy side at that speed. The brakes are mountain bike brakes, but it is a 120lb bike, so you aren't going to stop on a dime, and the brakes can overheat on long downhills. You can't take it on the freeway. In Cali, you can plate the Sur-Ron as a moped, but not sure if it is worth it to do so (I just got the moped plate in the mail yesterday, and the plate is wider than the seat!) Still trying to decide whether to mount the plate or not. It's fun, but it is more of a pit-bike size and power. I think I'd probably compare it to a KLX110 or similar, but quieter and a bit more versatile. It's still quite cramped for a full size adult (at least us guys over 6'), although I'd say they'd be great for shorter folks and especially kids and petite ladies. They're excellent for cities. Lots of aftermarket stuff you can do to it, mostly mountain bike parts. And of course, they are still in business!
The EXR is an all around better bike, real power, good commuting, excellent trail bike. Real brakes. Comfortable for adults to ride for more than a few miles. You can take it on the freeway. All the virtues of a legit enduro motorcycle, without the noise or maintenance. It checks all the boxes for performance, maintenance, ease of use, etc. And it is a classic already.
But why choose? The Sur-Ron is cheap enough to keep the EXR and still pick up a Light Bee. Take all the money you save on gas and maintenance with the EXR, and buy a Sur-Ron. Play around in the yard with the Sur-Ron or let the kids or neighbors ride it. Do your serious road/trail work on the EXR.
Or if you are just desperate to get rid of the EXR, I'll swap you straight across for my brand new Sur-Ron with all the upgrades! ;-)