Just like to say thank you vhristenco for spending time to create this process - very helpful and I'm now back at GB. I think I hit all the reported problems: no superuser till reboot into recovery, no wifi at B892 if upgrading from B882, can't then just update with B895 without going all the way back to step 3. So I would recommend a few alterations:
To the start of step 5 I would add something to the effect of 'Choose either B882 or B895 to flash, note that there have been WiFi issues caused by flashing B882 and then upgrading to B892 via OTA'
Change step 6 Windows section from 'launch GingerbreadRoot.exe. When it finishes, your phone will reboot.' to 'launch GingerbreadRoot.exe. When it finishes, remove the battery, wait for 3 seconds, re-insert the battery then power the phone while keeping Volume UP pressed. It will take you to recovery. From recovery, select "Reboot system".' (thanks for the tip vhristenco!) - can't comment on other OSs.
Potentially re-edit the 'As some people are having trouble upgrading via OTA to B895' paragraph or at least state that steps 3-7 must be repeated (and step 2 if they deleted their IMEI backup!).
I think these edits would capture most of the issues reported and make this a little more straight forward. Thanks again for an excellent post!