Did the same thing a few years ago when POP was brand new. In all honesty, as we drove up to the reosrt I was sure I'd made a terrible mistake...and told the CM at check-in that I wanted to switch resorts, if possible. It was also a last minute trip and money was tight, but still wanted to switch to a moderate.
The CM convinced us to give it a try and promised to find us another resort if we were still not happy. Soo, after taking a deep breath and walking to our room - telling ourselves to be lighthearted and enjoy a side of Disney we'd yet to experience.
Well, we were very surprised: walking past Lady and Tramp we could not help but smile...also surprised by our room - yes, it was small, but fine for two friends. It was in mint condition because the resort was brand new - we could enjoy seeing IllumiNations fom our window.
Because of that stay we tried POP 2 more times for short trips, but as the Resort became more and more popular, with such high occupancy, the rooms showed the wear and tear and it could be very noisy. We missed the way we could stay in a deluxe for 4 ngts, yet feel we'd been away for longer, so back to a deluxe.
Of course, we also stopped staying at deluxe resorts as the rooms became rundown and in need of rehab. We do try to stay at resorts that have been recently refurbished, be it a deluxe or moderate..or value.
Recently, when considering a last minute short trip, seriously considered ASMU because the rooms were recently refurbished. When I checked out the photos on the DIS and allears, found the lobby unappealing and the food court as well - yet loads of adults LOVE this resort!! I'd definitely request Calypso.
So, my suggestion would be to try to enjoy the new experience - it should be fine for 4 ngts. There is lots to miss not being at a deluxe, but a value can be okay too. Maybe you'll even find that it's a great optuion for a quick getaway
Hope you have a wonderful stay - be sure to let us know how it goes!
p.s. If you could handle it with the crutches, might consider requesting a 3rd flloor. We found the top floor quieter at a value. I have MS, so walking is an issue, but top floor works out well.