Iceberg did a nice
review of the 8000, some time ago.
Most of that thread should apply to your 8100.
It started in 2007, so be sure to read all the way through, as I'm sure many improvements are documented since it first hit the market.
As for docs 'n comments on the 8100 PVR, you're right - not much has been said.
Posting a review of the 8100 differences is still on my todo list! I'm taking next week off so hopefully I can collect some facts on the 8100 and post it. Since the PVR functionality is the main difference, I really need to test it out a bit and I haven't been using the PVR feature since I have a TiVo.
I did hook a drive to it last night, so hopefully I'll have something soon.
Meanwhile some things I think I have noticed that need investigation:
Loop out port appears to pass some signal when the Coolsat 8100 is physically switched off.
Loop out port appears to allow some power & signalling to be passed from the slave receiver when the Coolsat 8100 is ON and tuned to a channel. Changing channels or scanning from the slave receiver interferes with the 8100's signal and I think (needs to be tested again) the slave can even move the dish. As a result I use the 8100 slaved off the 6000, since the 6000's loop out port seems to block power and signalling.
Changing the channel sorting order doesn't stick after you do a scan. E.g. if you have sort set to network and scan something, when it saves the list after the scan it will be in the default SID or channel number sort. So you have to go sort by something else, wait for that, then go back and select network sort again. This was a real pain until I discovered the "FAV" button. (mentioned below)
Any rename you do on a channel will be lost when you rescan it.
The 32 satellite list thing is very annoying. Especially if you forget one. When you have to add it as number 25 instead of number 2, the satellites are not in the "correct" order and you have to manually move them all down one. If you won't use all 32 slots, I recommend leaving a few blanks in strategic locations. Less to move if you missed one. Or discover something ITC on a satellite that isn't in the list.
OTA is listed as "DTV" and anything that scans in is attached to a fake satellite a 90°E that can't be deleted. Confusing at first when you try to delete it and it says "satellite in use" with no transponders listed.
Some feeds that "green screen" on the 6000 will say "no video" which I need to confirm means it was 4:2:2 or not. Basically I hope I can PVR the TS on the 8100 and look at it on my computer. Otherwise I need to check with the 7000 since it seems to sort of record the TS. At least enough to look at the header info.
Some basic differences between the 8000, 8100 that I noticed:
8100 has USB & PVR. (obviously)
8100 remote has an extra row of buttons on the bottom.
8100 has a fan.
I need to compare the two units a bit more. Unfortunately the 8000 I bought off eBay for $51 is missing the loop out F connector. It was missing the LNB IN, but I moved the loop out over so I could use the box. I didn't have any organ donor tuners handy with the right connector orientation.
Oh and in the "non obvious features department.." (at least to me) the "FAV" button near the bottom of the remote works similar to the "SAT" button on older Coolsats, letting you select a specific satellite to filter the channel list by. This helps tremendously with the channel naming / numbering / sorting situation. Until I stumbled on this button I was pretty frustrated with the channel list.
All this being said, I think it is a very nice receiver, especially when slaved off a good blindscanner like the Coolsat 6000. I'm still working on getting a good OTA antenna feed into it.
It looks like I addressed things I found wrong mostly, but only because the great features that work (DVB-S2, HD, MPEG4, etc) are all covered.
Anyway, I'll test it more over the next week or so and post a better review "next year" or something.