Completely different levels if you are comparing them to the PL50. PL50 has a lot of mids, gr07 would be relatively much extended at the highs and the lows. Bass would be a solid improvement, except it is not on the boomy side. Test it with some songs that have extremely low bass, and there are notes where the PL50 simply couldn't produce them.
A very clean sounding iem without any faults really. PL50 is a very nice iem as well but its soundstage would be small and less 3D/real compared to the vsonic. You also don't have to worry about loosing any mids or details from the upgrade.
You've scored yourself a baby. Get excited already 
Quote:
Originally Posted by
RealSlimSeto 
Both are great. The greatest strength about them is their lack of weaknesses.
P.s. oh do not get too excited. They do not really WoW you, they just do everything right. I did not liked them that much before, but after owning them for a few months they are demonstrating their goodness in my every single head-on comparisons.