An almost off-topic, left-handed kind of response to your question but... If you're after low noise, easy to hand-hold at low shutter-speeds, inconspicuous camera, have you considered keeping the F3 and adding a TLR?
It's just a part of me shudders at parting with *that* much money for what is, when it gets right down to it, a 35mm camera. At least an XPan adds the panoramic ability (and *still* comes in cheaper)!
(Please direct all flames to dev/null! )