i would go for the mossberg o/u instead as a comparable gun. a friend of mine had the tristar and had intermittant misfires all the time. stoeger also makes'em.
Never tried a tristar, put a bunch of rounds through a baikal though, good gun for the money. So far no failures, but I don't do much shotgun work. Put the hurt on 8 or 9 pheasant last year though. I paid about $300 for it, I think they're more now though.
I don't recall any problems with the tristar autoloaders other than guys putting them together wrong, but one year I ordered 20 o/u tristars to sell because they seemed like a good deal. Nearly every one had to be sent back for mis-firing problems.
A friend bought one for his son. Nothing but problems. It wouldn't eject correctly and it mushroomed the brass. He sent it back for repair and when he got it back, it ejected O.K., but they didn't fix the mushroom problem. They wanted him to send it back again. I think he sold it.