The JVC/TY PrintPlus has a more opaque "center ring" compared to TY Watershields.
The JVC/TY PrintPlus can have a more pronounced line demarking the outer circumference of the inner ring area compared to Watershields. Also, the PrintPlus have a slightly rough and beveled appearance of about 1mm along the circumference of the outermost area the printable area.
The PrintPlus are considerably different in character and appearance that you will not mistake it for any other printable disk that I've seen from Taiyo Yuden or Verbatim.
I have not tried Aquaguard or any other printable media except for Taiyo Yuden (now JVC), Verbatim, and one spindle of TDK.
Watershields are the best appearing to me. I'd be fine with the PrintPlus if the disk quality scans weren't so horrible, and, if the price stayed significantly lower than Watershields. Otherwise, I'll use "regular" TY T02 printables and Verbatims (if TY quality continues selling crap quality for premium prices). I'd also like to try the highly praised disk quality scanning Falcons.
I should also look into the Aquaguards, but have had poor results with Imation and Memorex several years ago and never tried them again.