Depends on where your bashing. They hook up pretty good on loose stuff, but they are really squirrelly on hard pack and pavement. Concrete/blacktop will grind the down quickly. Running in grass will give you constant roll overs.
I bought a set of 4 with wheels for $35 shipped. The guy did a horrible job gluing them and I spent an hour or so cleaning up the bead and dremelling down to plastic so I could re-glue properly. He glued to the chrome...
They are a lot harder than I would have expected. The sidewalls are pretty stiff and the rubber compound is stiffer than stock 2.5 maxx rubber.
For general bashing, I still prefer the losi zombie maxx's. Those tires give you great grip on just about any surface. They are pretty soft, so if concrete/pavement is where your going to run, go with something else as they will get ate up pretty quick.
When I know I'm going to run on concrete, I have a couple sets of 2.5 maxx wheels/chevron tires that I run. Those things last forever, but they don't hook up on a track very well. Great for general bashing around though. You can normally find them pretty cheap on ebay as well. I've bought 4 tires/wheels @ $30 shipped a couple times. Now that I run a lot at an MX track, I don't use them much. I use them for engine break-ins though.