DSI Pro question

I'm looking at the adds for the DSI Pro. I have also looked at the adds
for the original DSI (colour). The maximum exposure time for either
camera is supposed to be 1 hour. Has anybody ever tried this ? I ask
because the sample images are all stacked up 30s exposures. I haven't
seen any individual exposure longer than 30s. Also, anybody know what
the well depth and read noise are ?

Thanks.

Eric.