I love my BX500. It may not sound the greatest when you set all of the EQ sliders and knob to the middle/flat position but it can sure sing once you adjust them accordingly. The BX500 offers plenty of flexibility. I didn't really have to toy around much at all before I found something that sounded great. I don't mind that it doesn't sound perfect with everything centered; there's no harm in using the EQ to make fine tuned adjustments. 
The main feature of the Carvin that had me sold on it was that it is stable down to 2 ohms. Also, my past experience with Carvin played a role; I've got a B1500 and it's an incredible amp. I have a pair of 112s that I use with the BX500 and they are both 8 ohm cabinets. I don't regularly utilize the 2 ohm stability but I have considered getting a matching Avatar B210 (4 ohm). I like having the different cab arrangement choices, even if I rarely take advantage of them.
I've heard terrific things about the Markbass Little Mark heads. I would definitely like to try one out sometime. If I hadn't gotten the Carvin then I would have definitely waited to find a used Little Mark II or Little Mark III. I'm sure that all of the praise is well deserved.
The main feature of the Carvin that had me sold on it was that it is stable down to 2 ohms. Also, my past experience with Carvin played a role; I've got a B1500 and it's an incredible amp. I have a pair of 112s that I use with the BX500 and they are both 8 ohm cabinets. I don't regularly utilize the 2 ohm stability but I have considered getting a matching Avatar B210 (4 ohm). I like having the different cab arrangement choices, even if I rarely take advantage of them.
I've heard terrific things about the Markbass Little Mark heads. I would definitely like to try one out sometime. If I hadn't gotten the Carvin then I would have definitely waited to find a used Little Mark II or Little Mark III. I'm sure that all of the praise is well deserved.

