Other than the location and the gym, this hotel is [don't know what words are allowed that mean garbage]
The Hilton is fantastic, Sheraton is great if you don't mind taking a taxi. PPOrchard is to be avoided and just stay away from Orchard Hotel
If you're looking for budget, then Hotel 81 or a Fragrance isn't so bad if you don't mind banging on your walls (to be fair it's not that often)
Changi CP is great. But on that day, you may be better off rerouting your flight to be somewhere more cheap and interesting. Bet you can find something in:
KUL
BKK
SGN
CGK
...
Even ICN/GMP/HKG/KIX
anything else in the world on that weekend may be cheaper maybe even counting the rerouting/flight costs