Cat 3406E or Volvo Penta D12-700 - Fairline Squadron 58

Hi guys,
I'm hoping to pick your brains a bit about engines. I've been running a 42' Sea Ray with Caterpillar 3208's (the 375HP's, of course). They have been very reliable. I'm considering a Fairline 58 (used). The ones on the market have either Caterpillar 3406E (800 HP) or Volvo Penta D12-700. Both engines propel the boat very nicely (I've seen reviews with both engines), and I'm leaning toward the Cat's because I've had good prior experience with them.

However, smoothness, fuel consumption, and volume are very important to me (reliability too, of course), and I've seen a lot of good things written about boats with VP engines in these characteristics. I do not have any experience with VP engines, and I'm not knowledgeable about them. I am hoping that some people here might have some insights about one or both of these engines.

Thanks!