Artesian owner here. Obviously the best thing to do is wet test both if you can.
One thing I can say is that I really like Artesian's individual seat controls. It's nice to have your own dedicated pump that you can vary the speed of, and add air if you wish, without having to compromise with anyone else in the tub. Sometimes my wife wants jets and I don't, or vice versa, and if you only have one smaller pump going with no air it's really nice and quiet.
A counter-argument is that you can't direct all the output of a larger pump into one seat with a diverter. The 1.5 HP (3 BHP) pumps are enough to give me itchy back, but if you really want a hard pounding you might be better off with larger pumps shared between seats with a diverter. It's a tradeoff between maximum available power vs. convenience and individual adjustability.
As for reliability, there are more pumps to fail. But if it's usually just two of you bathing (as in my case), you'll only be racking up the hours on a couple of the pumps. In the 16.5 years we've had ours, the only failure we've had was the heater, and I suspect that could be blamed on a couple years in the middle where we didn't use it much and weren't paying attention to keeping the pH up. I learned my lesson. That's just one anecdote though.
I have no experience with Marquis and haven't even wet tested one. So I can't comment on the brand comparison.