I think there are one or two nuances/details missing from this discussion. Because Mark introduced the changes to the two courses in a single post, this maybe allowed some to infer that there is some sort of symmetry in terms of the scale/ambition of what both clubs are doing. I don't think this is correct.
One - Merion - is embarking on a very ambitious, expensive and quite controversial project.
The other, Pine Valley, is in the middle of a makeover which did not seem contentious among members i spoke to, and certainly nobody talked about cost. Also, it is being done broadly within the normal cycle of when the club is (mostly) closed, whereas Merion will close the East course for 18 months (effectively one full season). Among people who belong to both clubs, the talk was all about what was happening at Merion, not Pine Valley.
For what it is worth I agree with Mark's comments that the changes at Pine Valley are a huge success. They have done a great job at exposing some views and exposing more sand. The only criticism i heard of a GCA nature was that the work done below the 2nd and 18th greens, and to the left of the 5th, is slightly artificial inasmuch as it introduces bunkering whereas originally there was just sand, but not really bunkers. So, by this reasoning, it is an improvement, but not a complete return to it roots.
Visually the greatest changes are in the approach to the 2nd; the view of the 3rd, with much more sand now visible; greatest of all, the 5th where there are far fewer trees close to the green. Overall the changes behind the 9th now make it perhaps the most visual hole on the course - perhaps why it is now on the front of the score card.
As for Merion, I think Ed has captured the essence. The project is an overhaul of the greens, not of the course more generally. It is certainly true that the surface (softness) and slightly blotchy appearance of their greens was some way behind that of Pine Valley and Applebrook, the other course we played. But they still putted well. Whether this is a "problem" that requires $15m to remedy, and whether members will feel it a good return on investment is, i guess, a matter of taste and time.
Among those unhappy about the changes, there were two main gripes: one being the cost and need to take on debt. The related concern was that the changes would really only make a difference about four times a year when the course was subject to very heavy rain. The new greens will allow the course to re-open maybe two hours earlier than with existing greens.
The one substantive change that will be made that i have not seen mentioned is that they are going to move the 2nd tee a little bit forward and down the hill, while the green is going to be moved a bit further back.
Although the premise is that the aim is not to change the shape of the greens, a member who had been through a similar experience at Winged Foot was confident that an exercise likes this will necessarily end up introducing more change than is originally intended/disclosed. This was based on the view that the architect is more an artist than an engineer (my words, not his) so some licence/perspective will be introduced along the way.