It turns out you were right I had the wrong settings in the BDP, so I fixed to bitstream for the digital output, and now when detecting dd5.1 the surround light turns on when the PL2 is off.
Now, I did the test again, set back the BDP to PCM 2ch and listened 10 min of prince of persia, then I set it back to bitstream and listened to the same 10 min; and I could not tell the difference regarding the surround effect, though, in PL2 the volume had to be on 32 specially for the SW, while in dd5.1 23 was more than enough.
However, even though I could not tell the difference, there is difference indeed; it is just that for me to be able to notice it I had to perform the test over again, but this time, I tried very very very hard to pay close attention and listen carefully specially at the surround speakers… and bingo! I finally was able to notice something different besides the volume level needed for the PL2 to sound like dd5.1.
When listening very close I finally noticed that in dd5.1 the separation is better (very clear difference between sounds, no background noise) for instance in a scene where horses are running, on dd5.1 only the wind of the desert can be heard from the rear speakers and the horses noise comes from the other speakers. On PL2 the wind comes from the surround speakers but listening carefully I was able to hear the horses noise as well on the background, very low but the sound is there, which means that the sounds are not totally separated, just the volume level are reduced in some of them to enhance the sound that is supposed to sound in the surround speakers.
Now if you ask me, I think that PL2 does a pretty good job "faking" the dd5.1, because, at least to my ears, I can tell the difference only if I'm focus hard to listen to the background sounds, and pay really close attention to the sounds separations, otherwise when focused on the movie I cannot notice it at all.
The only thing I have to do using PL2 is turn the volume higher, though, no too high because it seems that there is a point where the more volume you increase the more the background sounds are noticeable and then the fake dd5.1 is pretty evident an noticeable.
I don’t need to use PL2 because my receiver supports dd5.1, though, I would not mind to use PL2 if I need to. I don’t even will use it for the TV, because I'm getting a digital input splitter so I can have dd5.1 using both TV and BDP.
I guess if someone is too picky and is always looking for flaws, definitely will find them. But for some of us that are not that picky and can leave with some flaws in thinks, won’t be able to notice it. But that is just my opinion.