I'm new around here, but have a little experience to share.
Like you, I am also considering a 912 (or 902) for reading pdf's - seems to be a common use case, understandably.
I have a PB 360 (the original one) and while I get the screen inversions, I really don't notice them. I think I might have, originally, a year or more ago, but not for very long. OTOH on a big screen it may be a bit more painful. I, too, saw some comparison videos, and it looked like (but may have been down to book choice) the 912 was blanking on each screen while the 902 wasn't.
With regards cropping - the M92 did have that nice feature where you denote a border with a diagonal strike, but something I recently discovered via the nice people on this forum is probably even better - BRISS
. It does mean you need to process a PDF before popping it onto your reader, but you can get it *just right*, and the software produces a snipped PDF in several seconds.
As to whether there's any new models .. steady on there chap - it's virtually impossible to find any of the *current* models for sale in Europe at the moment!