I tried it out the day the patch came out, it's pretty shit with only 2 mismatched screens though.
I can confirm that it does work with a combination of OFW and CFW, I had the gt5 disc in my OFW PS3, while loading from the hdd on CFW on the other one. There was a slight decrease in image quality on some track backgrounds, if you put your one ps3 into "server mode" you should see what I am talking about.