I ordered a PlayonDVRHD 75120 for my birthday in March and after a long wait in July I received a 75120 with a free wireless n adaptor due to the long wait. However this unit was faulty which was overheating and crashing due to the board not running the fan. AC RMA'ed the unit and gave me the option to wait for the new version 76120 to which I would have to wait for again.
Anyway I received the 76120 on the 10th August and here are my thoughts.
1. The build quality is much! Better as it’s not all plastic and looks much more like a professional product.
2. I think they have improved the remote control. I don’t really remember the old one much but seem to remember some layout issues to which I don’t seem to have on this one.
3. The unit is a bit bigger which is a bit of a downside but it should help in cooling.
4. The tuner is one unit so there is no daisy chaining the tuners with coax cables like the last one.
5. It looks like the tuner is replaceable maybe for a future DVB-T2 tuner (I hope).
6. The player has played every file and codec (including 1080p) I have chucked at it without any stuttering or lipsync which sometime I got on my PC.
7. AC supplied a lot of fairly good quality cables with this unit which you would not get with other players.
8. I have installed a 2TB WD green and cool media HDD without any problems or overheating.
9. There have been 2 revisions of firmware to which I have installed and the process is very simple.
10. I have found is that there is no security on the web server and this could be problematic if you want to enable the remote scheduling feature as the world would have access to your unit. The security feature is in the instructions but just not available on the unit as per firmware r3582 (AC should be able fix this in a firmware update).
11. It seems slow flipping between channels especially so if you enable permanent time shift function.
12. It would be good if you could flip channels thought the info bar without it changing the channel to ease the pain of slow channel flipping.
13. The Bit torrent part of the unit does not seem to be compatible with some sites that restrict which torrent program you can use, which is a problem for me. Would be good if you could load your own BT program but now I’m asking far too much

It is early days but so far I am really impressed with the unit and it was worth waiting for the newer unit. Im sure AC will further develop the firmware and it can only get better. I will post more findings as are start using the unit more.
Although I have had many long waits and a faulty product to start with I do feel that AC want to look after there customers . Keep it up AC