I've had my BX1500 since July or so and no issues what so ever.
I do own a lot of Carvin gear and the only issues I've ever had were trivial stuff that they corrected immediately. I ordered a custom finished X100B (guitar amp) with a two tone finish and the modern logo and knobs, something they had never done before, so there was a minor issue when I went to pick it up in that it still had the vintage logo on the head and cab. 5 minutes later it was fixed and I went home with an awesome amp.
Another props to their customer service is that I took my C66T and LB76 in for a set up and pot cleaning on the guitar. I figured I would have to drop them off and pick them up a few days later. Coincidently the SB's had just come out so I started noodling on a couple of those, and when I went to leave the sale guy stopped me and told me not to forget my guitar and bass. Huh? They were already done, showroom clean, new strings, perfect string height, all within about an hour?! Awesome!
I do have an advantage (or curse) of living within a half hour of Carvin HQ and I'm sure that helps but from talking to several members of the Kiesel family they really do seem to care about their customers.