Hi Jase
Well if it's free, who cares?!!
We've been using the LX54 in our middle demo room (along with the BDPLX91) and not really had many issues yet, but then, we don't have thousands of films for demo! The only one I know that failed to read was Mamma Mia (which I'm actually quite glad about, as I've avoided any sight or sound of it thus far). I've got Inception, which I'll take into work tomorrow and see if I get a problem.
Lip synch issues vary from film to film, and in some cases, scene to scene. Most amps will need to be set to about 90/100ms delay, although I've had some films up to 270ms.
I've never used any YouTube type functionon any Bluray player, so can't really comment on that side of things - our demos tend to be playing Blurays or playing CD's