I would switch to GF. Love watching the fireworks from across the lagoon. I actually prefer GF pools to SAB. I also like GF QS and TS better than YC/BC. Also like the easy access to food at Poly and CR even when it's hot and/or raining via the monorail.
I agree with all of this. I've stayed at both, even doing a split stay between GF and YC a couple of years ago so had an immediate direct comparison and don't get me wrong, BC/YC are not bad resorts at all. But by nearly every metric YC felt like a step down to me. I understand why people love them so much, and I definitely enjoyed our short stay on last month's split, but those resorts are carried very, very hard by their location. Which can be had at S&D for a fraction of the price, mind.
Thought it was just me on the pools. Maybe if we had teens or older kids, but even after giving it another shot on this last trip, SAB is too crowded and too much for me. Far more so than the GF pools. Finding chairs felt so stressful at SAB by comparison. I will say the quiet pool was absolutely dead there, probably because it flies so under the radar.
It's the food for me though. The monorail loop has all my favorite resort restaurants, QS and TS. The QS lineup is pitiful at BC/YC and there really isn't anything better around Crescent Lake unless you hit up Fuel at the Dolphin (which is severely underrated imo). Yachtsman and Ale & Compass are the best things going there. You do have the easy access to WS and festival booths of course (as long as you're trying to eat after 2pm), but if you don't feel like going back into the parks you are limited there in a way you aren't at GF imo. And being all in one building is a blessing and a curse. It's nice in inclement weather. But not having any real grounds bc it's all pool contributes to a very samey feeling to the spaces at BC/YC. I love having landscaping and grass.
OP, it really depends on your priorities. I would switch in a heartbeat but I go enough and am familiar enough with these resorts that I know what I like. I would still be inclined to switch unless Epcot and HS were major priorities for you, with multiple days planned. GF is not likely to be discounted again like this any time soon with brand new rooms, it took Poly about 2 years to offer even modest discounts again after the Moana revamp.