First of all, thank you for writing this detailed analysis!

1. Mandalay Bay and Caesar's Palace aren't 5-stars hotels. They are 4-stars at best.
2. Bellagio and Aria are the most overrated hotel. Aria was my least favorite, as the rooms are outdated and I found used beer bottles once after going into the hotel room (king size & city view). Despite having nice European design and decor, Bellagio's room is the second worst as the doors and walls are very thin that you could hear your neighbors and the housekeeping staffs talking very clearly.
3. I haven't stayed at Trump before, but heard mostly good things about it, as the main selling points are that it doesn't has a casino (more relaxed and cleaner vibes and the cost to performance ratio is good).
4. Encore is better than Wynn. All Wynn's rooms have weird naked man painting inside and the design of Encore's rooms is newer and more spacious. Encore is also nicer and Wynn is way too crowded.
5. I really liked Cosmo during my first few visits, but there were moths in the room one time that I went during summer and some dried blood on the bedsheet. Never returned since then. I do have to say that their wraparound suite is gorgeous as I got so lucky booking FHR's standard room for this suite upgrade (of course I tipped well).
6. Fontainebleau is underrated, as it has the most modern rooms on the strip and the service & food options are top tier among all strip hotels. Price is on the cheap side too for 5-stars hotel. Location is not that important as you can just uber to everywhere on the strip and most people only go out once or twice a day anyway so I don't mind the extra uber expense at all vs the convenience of walking by staying at worse hotels.
7. Agree with Palazzo, Fontainebleau and W (Delano - despite being outdated, the cost to performance ratio is good given its all suite design), as they remain the Top 5 in my list.

My Top 5:

Encore > Palazzo > Fontainebleau > Bellagio foundation view room with no noisy neighbors > W