This playlist mostly consists of install videos, but in the description of each install video for the parts I installed you will find the links for the website to the items and links to the google groups to read up on others opinions and questions about the upgrades.
A few updates I have done since I took the printer to the meeting are:
1. Replaced the stock bushing in the carriage with linear bearings - video coming soon. Just needs edited.
2. Replaced the stock X cables that tend to beak connections from aware with adafruit cable. Video is in the play lost for this. This is a great cable for any printer was has constant motion on the cable and it's made of silicone so it can handle surviving in heated chambers.
Other little updates I have done but didn't do a video on them are:
The ABS air scrubber:
http://www.thingiverse.com/make:76712
And end stop reinforcers:
http://www.thingiverse.com/make:80333
I have not done any reviews on these products and probably won't since I have them all installed currently. The only thing I can tell you is it runs great, does ABS, nylon, and of corse PLA since that's what the R2 was originally designed to run and others. I have not tried PC yet, but seems like I would have no problems printing PC with my updates since my research shows that other have printed with it.
The playlist link is:
http://www.youtube.com/playlist?list=PLpXy7eev4S13bBGjrHGk1ds86EbNfa_Cf