So in the end, I had a good experience at the Riviera and in the highly unlikely chance I return to Palm Springs, I would stay here again. I've shared my good experience with a couple other friends who were aware of the hotel's bad reputation for some of the issues raised in this thread and they will give the hotel another try.
Pre-arrival: My suite night awards cleared and I was assigned to a Jr Suite. I was planning on calling the day of arrival to make sure I was in Bldg 1-3 as suggested, but then I found myself re-assigned to a Deluxe Suite. The call was a little awkward as the receptionist could not figure out how or why I was in a Deluxe Suite, but we sorted it out and she assured me I would be in a quiet area, although it would be Building 5.
Arrival: I arrived late evening and was the only person in check-in, but I immediately saw the problem - the chance that staffing and desks are not sufficiently manned at peak times leading to a chaotic scene in the rather tight lobby. Check-in was simple, status recognized, but no discussion of resort fee (and I didn't bring it up). Asked about breakfast and was told either points OR a continental breakfast...took the points.
Room: A big suite with dining area, entry foyer and large bathroom - the room was absolutely gorgeous for those into mid-century modern design, and probably a dark, dingy hell for anyone who doesn't know mid century modern from a cheese puff. I just loved the room and how it was updated without actually looking updated - the original styling was maintained with period accurate furnishings, colors and accent pieces, and I was instantly transported to the 1960s and heyday of desert modern design.
Amenities and Ambiance: Wifi was free for Platinums and performed reasonably well. The fitness center was updated and well appointed. The hotel was very quiet...no trace of parties, screaming, drunks, etc...but we checked out Dec 31, so things probably changed the night we left. Oddly, we were on the top floor, but heard foot steps from above on both nights...which left us wondering......The hotel design and decor is absolute design porn for anyone with even a slight interest in vintage architecture.
Restaurant: we tried the restaurant one morning for breakfast after trying one of the local breakfast hotspots nearby the hotel and finding a wait of almost 2hrs, as if Jesus himself was making blueberry pancakes - is breakfast something special in Palm Springs? The restaurant is slow....painfully slow. We ordered fairly simple dishes, but they took forever to come out and the food was just average quality. We did not receive any F+B discount for breakfast.
Check-out: This was our first experience during a busy period. Inadequate desk staffing, no obvious line-up area and the SPG priority desk was un-manned until a few more people joined the line. I asked one agent if we could just go to that line as SPG Platinum and she said no...but we ended up at that desk anyway and asked why and the agent apologized and said management was not using it at that point because the signage was not ready...which to me is a lame excuse for not offering priority service. The carpet was down and all the agent needs to do at that desk is call out to SPG Plat or Gold guests to come forward.
Anyway, our resort fee was comped at that point, the agent was very friendly and promised priority service was coming soon.
After we stepped away, two other people cut the line and came in behind us, apparently SPG Plat or Gold and were served next - which is not really the right way to handle guest traffic...hopefully they have this process cleaned up quickly as it shouldn't require more than 10 minutes of training and a decent amount of common sense for an experienced hotel manager to figure out how to do this properly and have the process in place within 24hrs not within weeks or months.
So overall I see great potential for the property once they sort out some process issues and ensure the environment is comfortable for everyone regardless of room location - meaning enforcement of noise curfews and party behavior.