If you have the money, and you don't mind spending more, I would suggest the Dune Smart Series over the PCH. In my opinion the Dune is just easier to set up, and you have more jukeboxes to choose from, and you can change the way the UI looks.
However, I do agree with Halflite about the Dune prices. Dune hardware has not been updated for a long time, and I don't believe it will be updated at all. The PCH-A300 has some slightly better updates than the previous PCH-200 series.
I've got a Dune D1 in the living room connected to a 7.1 surround sound, and the UI and Zappiti jukebox is excellent. Zappiti is simple and easy to set up and use.
I was thinking of buying another Dune player for the master bedroom to replace my AIOS, but the price increase made this impossible. I was lucky enough to find a PCH-A210 in excellent condition and bought it for $120.00 dollars. I've been testing the YAMJ / Eversion jukebox, and it took me a while to understand how to set it up and run it.
Another thing is that the PCH-A300 has an internal jukebox. At the time I had the A300 (when it first came out) it had a lot of bugs, and the jukebox would not let me edit anything. However, PCH has made some updates, and it appears that this has changed, but a lot of A300 owners still use the YAMJ / Eversion jukebox instead. The other issue I had with the A300 was that it lost sound whenever I played a movie with HD sound. I was able to get the sound back by using the secondary sound track. I always rip all my movies with a secondary sound track. I've heard that PCH had a FW update, and that it fixed this issue, but I've also read that some people are still having some sound issues.
I haven't had any issues with my Dune, with the exception of not being able to play an BD ISO movie with full menus. It wouldn't even play it with lite menus either. I usually do not rip BD movies as ISO, but I wanted to test it out, and it didn't work out for me. I mainly rip my movies as main movie only M2TS file with ClownBD / AnyDVD HD.
The only thing I do full ISO's are my TV shows, but there are DVD's ISO and my Dune and AIOS media player did not have any issues playing them.
As Halflite mentioned, you cannot go wrong with either Dune or PCH. I know that PCH's are pretty much out of stock, and they only order them after getting a big batch of orders. It took about 4 weeks to get my PCH when I pre-order mine. It took 1 week to get my Dune D1 frome diamonhomedesign.
You can also read the review done by Damian / dbone1026: