why are some blackjack tables faster than others at the same casino.

So I noticed last night that two blackjack tables just a few feet from each other were moving at completely different paces. Same minimums, similar crowd size, even the same pit boss rotating between them. One table just seemed to be burning through hands like crazy, while the other was crawling. Is it just down to the dealers and their shuffling speed, or does the table vibe play a role? I was tempted to jump to the faster table, thinking I'd get more action for my money, but then I started wondering if there's an advantage to sticking with the slower one. Does anyone here actually prefer slower tables, or do you always aim for the fastest pace?