I have not tried any of those but I just bought the Wilco PIC 737 Classic which is half price right now ($25) and am REALLY impressed by the flight model! The worked with a 737 Captain to develop the product and he made sure the flight model was perfect.
I am not a 737 pilot, I am a severely under employed CFI waiting for airlines to call me, but a friend who is a 737-400 Captain told me what the power settings are suposed to be for various speeds and flap settings and I think it is really close. I also have an in the cockpit video of a 737-400 (and a couple others) for maximum nerd factor!
IF Wilco had an A320 pilot verify the flight model it is probably good, but I know that a lot of simmers LOVE the PMDG stuff.
My computer can't run the PMDG stuff. By the way, I'm running FSX, but the Wilco PIC works on 2004 also.