The PA10 gen 2 uppers and lowers will be out shortly.
The new uppers and lowers are functionally compatible with the earlier Gen1 uppers, lowers and parts.
The Gen2 PA10 has a more streamlined appearance. As you can see in the photos below, the raised section of aluminum that runs vertically on the magwell has been removed, and the lower has a flange, at the top where it meets the upper, to match the widths of the two. The Gen2 upper receiver is wider at the base, but the overall width remains unchanged.
However, there are cosmetic changes that may make mixing and matching Gen1 and Gen2 uppers and lowers less than aesthetically pleasing for some.
Here is an example of when a Gen1 upper is coupled with a Gen2 lower:
The raised vertical feature on the outside of the magwell actually starts on the upper in the Gen 1 and is carried down onto the lower. The gen2 lower does not have this feature. In addition, the shelf at the top of the gen2 lower does not match up with the gen1 upper.
These differences may not be a big deal for some, but it may be for others.
Gen1 lowers will be available in the future for those who desire a Gen1 matched set.