Resurrecting an old thread, just got a PL50 new on eBay for £20 and love them. They're definitely a step away from the Soundmagic DD range, but as a single BA that was expected. Extremely balanced top to bottom and very good detail levels in the mids and treble. Just smooth enough not to fall into the cold analytical category... tho they aren't what I'd call buttery smooth as note weight is slightly thinner. Bass is light but far from gone. It's fast and can reach the notes in bass-driven music whe it needs to, just with faster decay. I love how open they sound, imaging is excellent... so the soundstage is accurate.
The closest I'd say they get to in the Soundmagic DD range is the e80, the main difference being the e80 has more body and weight but they share the same brightness and detail in the mids and treble. When I compare them to the budget Brainwavz BA range, they're less warm and cozy than the B100/150/200, but they do sound closer to the B400 with was their flagship of that particular range.
The PL50 sound great with orchestra, classical and jazz as their open, airy and detailed signature does those genres a lot of justice. BUT I still really enjoy them with everything I've thrown at them as they are very faithful to the music. The P50 is your classic, old school Balanced Armature signature. These days I find single BAs have added weight the sub-bass region giving them a full sound... well the ones I have anyway.
These are popping up more often and if you can get one cheap they're defo a fun pair to have. They're tiny and super comfy.