Primary differance between the PS3 and everyone else -- The Hard Drive! The PS3's hard drive enables the PS3 to run faster on just about everything when it comes to Blu Ray. The latest Panasonic models come close on load times, menu access and restart times but the PS3 is still top dog on those measurements.
Now with PQ several standalone's have surpassed the PS3 when it comes to upconverting DVD to 1080i/p. Samsung with the HQV chip, Panney with their own and Sony latest standalones all do a better job. As for Blu-Ray PQ most have stated that the new Pannys and Sonys have a sharper or more colourful display then the PS3. If you have the latest in 1080p tech on a new HDTV then that might be true. However, the PS3 PQ is no slouch and the differances are not night and day -- they are miniscule at most.
Sound wise, standalones are using audio chips to decode the new high definition sound tracks while the PS3 uses software to do the same for DTS-HD Master. If you need analog out for delivery of that sound to an older receiver that does not have HDMI then you need to stay away from the PS3 as it only outputs its HD sound tracks over HDMI. I have noticed that the PS3 when playing back the DTS-HD Master soundtrack that it runs hotter and therefore the fan noise is more prevalent - causing me to turn up the volume - not neccesarilly a bad thing -- but it is my only pet peeve for the PS3. It should be noted that I have a first release 60GB PS3 and that the newer models do not exibit this trait.
Right now the Panasonic DMP -BD55 is the best bang for the buck for analog out on BluRay and the Panasonic DMP- BD35 is best bang for the buck (currently $199 at Costco's) if you only need HDMI.
The PS3 plays games and also surfs the internet (not as easily as your PC) and is an excellant media player (especially playing back pictures and video from your digital cameras).
Which takes us back to the hard drive of the PS3. Almost all (if not all) of the standalones require a SD memory card to become BD-Live. It is a very limited amount of memory. Until someone drops a minimum of 8GB on the motherboard of the standalones then the PS3, IMO, is still the best buy for a BD player - especially if BD - Live is very important to you. Also, I believe the memory is what helps the PS3 (along with the Cell chip) in accessing menus and starting the PS3 so quickly. The PS3 as a BD player is lighting fast compare to current BD standalones on the market. When using the bluetooth remote the PS3 acts as fast as you can push the button. The standalones are lightyears behind this. Waiting 2 to 4 seconds for the player to react to pusing a button after using the PS3 for a BD player is excruiating. Also, restarting a BD on the PS3 is very quck. When the standalones can at least keep up with the PS3 on at least the menu options and have adequate memory-on-board and not in a SD card then I will buy a standalone.
My only displeasure with the PS3 is that at times the fan is too loud (as meantioned during playback of DTS-HD Master sound tracks). Of course when I crank up the volume unless there is a very quiet sceen during the movie I do not notice it that much. Most standalones seem to make their most noise while accessing the menu and menu options. I still think that the PS3 is very quiet accessing menu options and when it comes to playing any Java based material on the BluRay the PS3 still holds a sizeable lead in access time and playback- once again due to that Hard Drive.
But, if I were buying right now and I was not a game player -- then there would be a Panasonic under my tree. The new Panasonics are very nice players all around and with their ethernet port are very easily upgraded. With a SD card they are BD-Live capable and they have not exibited any problems playing newer BD movies. Good Luck on your choice and enjoy -- Blu Ray really does make a differance.