Ping calls its gap wedge a "U" wedge!!!
I always hit my gap wedges with a full swing so I prefer the gap wedge that comes with the set, as opposed to a 50 degree Vokey or Cleveland wedge.
Speaking of semantics that same club is called a Gap Wedge, Approach Wedge and don't forget the Dual Wedge ( marked with a "D" on the sole.)
They are indeed essentially all the same club with loft from 49 degrees up until you border on the "Sand wedge" which starts at approx. 54 degrees ...
Another thing that has made this issue more complicated besides the multiple names is the often great range of lofts using the same name. OEM's have strengthened most lofts in virtually all iron sets in recent years in order to market them as "longer" than the previous 7 iron etc. For Example, Many of todays 7 irons are yesterdays 6 irons - no wonder we hit that new 7 iron so much longer!! LOL
I read the article on loft creep. Good points, except it missed key event.
First loft creep was a move by early Ping designers to preserve distance, not gain it.
The original Ping iron designs with perimeter weighting produced a clubhead that got the ball up quicker and higher than standard muscleback designs. But, with the higher launch, Ping found that their 7i didn't go quite as far as a well-hit muscleback 7i. So, Ping strengthened the lofts a couple of degrees to protect distance.
Golfdom's marketing guys heard about this, and decided, let's do this too and say our 7i goes 155 yards instead of 150. Then, the loft-creep arms race was on.