Ducati's make great track bikes. Or so I'm told, never having owned one. Reliability on them isn't as good as what the Japanese standards are, but it is not bad, and quickly improving. Until the 1098 they were pretty well overpriced, but now only moderately so. Their desmo system requires more maintenance, which is likely to cost you more money per hour, since dealerships tend to assume that you can afford it.
I would guess that Suzuki's probably have the higher customer loyalty, I suspect this is due to them being the cheapest (if only by a small amount) and thus most likely to be someones first bike.