OK, I just tried OZ 3.5.2 on my C-700, and to make a long story short (3.5.1 was not usable, 3.1 was usable on my 5500, etc...), these are my main problems:
-each time I put the C-700 to sleep using the back button (not the menu), I come to an endless loop when I switch it back on (problem already present in 3.5.1). Each time I switch the machine on (back from sleep), there is a seconds long pause, at the end of this pause the machine switches back to sleep (when it was switched off using the button). It looks like the "off" keypress is put in a buffer that is not cleared before sleep, and is read back once the machines awakes from sleep (note this is how it LOOKS LIKE, I have no idea if such a buffer exists).
-installing packages using the graphical interface does not work (packages do not appear in the tabs)
-I don't see how to use my wireless network card. I would like to use wep, see no menu to enter it. ifconfig does not report a wl interface when the card is in.
-I don't see how to use ppp via IR (for internet access via my Nokia phone).
Admitedly, this was just a quick test, but those sticking points prevent me using the machine for much more than a quick test anyway. And reading the other posts here, it does not seem that everything is really smooth...
This being said, I feel horribly sorry because OZ is a volunteer effort and I am here complaining. Let me thank all of you for your efforts, if it were only Sharp I would not have bought the machine at all (I don't read japanese), so... A few positive notes: datebook read my appointments (from tkcalendar) without problems, the slider for the backlight is really cool, dito for the battery icon.
I also installed 3.5.2 on the old 5500, but did not test it. I noticed that when booting, the C-700 reverts to 1/1/1970 (mild nuisance), the 5500 does not.