Yo dexter_fan,
I own a Mauriat 66R, I have tried a Jupiter 889, and I will be trying a Kessler Custom in a couple of weeks (I'm visiting my buddy who has one).
Here's the low down on the Mauriat and the Jupiter.
Ergonomics: Very similar feel. Both based on the Selmer layout.
Intonation: Again, both have great intonation.
Tone: Here's the big difference. I am a Martin fanatic, due to the TONE of the Martin saxes I've owned. Big, dark, powerful...... The Muariat has this in spades, where as the few Jupiters I've tried (they seem to be very consistent) remind me of Yamahas. What can I say?....The Yamaha sound just doesn't do it for me. B&S tenors were a very close second to the Mauriat for me. The B&S tenors I've tried had a great sound, but the Mauriat tenors are the closest in sound to my Martin I've ever found. So for me it was an easy decision, P. Mauriat 66R all the way!!!!!
I know it'll be a few weeks, but I'll post my impressions of the Mauriat/Kessler comparison.
later
Joel