I received the 53fd and hooked it up today. It is replacing my 23fd and I can tell you that this unit is WAY FASTER than the 23fd is at loading blu rays!! That's a huge plus and one of the reasons I bought this unit.
I've had zero issues with the disc tray or with the unit freezing. With that said, i did a lot of swapping out of movies and a lot of stopping and playing and adjusting settings in the movie (about 2 hours worth of fiddling around). So as far as reliability and speed I'm very pleased.
The only issue I've had so far, and it may not end up being an issue, is that it doesn't seem that the Full RGB setting is the same as the 0-255 RGB setting of the 23fd unit. I found this by using the spears and munsil calibration disc. On my 23fd, in order to see the contrast correctly and not have clipping, I had to use 0-255 RGB setting. However, with Full RGB selected on this unit, it clips the contrast almost entirely. It's very frustrating. It may be a simple setting that I'm missing. I've managed to get it to where I'm ok with it, and the picture quality is great. (please note that this issue may be a compatibility issue with my projector, so others may not have this issue)
I'm very happy with the unit so far and I hope to find the correct setting to get the contrast in check with the calibration disc.