Air Arms AA S510 Ultimate Sporter XS vs BSA R10 SE

I have an AA 500 HFT and it's deadly accurate, but bear in mind it's a 12 fpe gun. I would choose an AA 500 for two reasons: 1. It has a power adjustment feature, 2. It shoots up to 20 fpe. Or you can choose the AA 510 because it's a repeater. I have no experience with the BSA, but it has a good reputation. The BSA is not regulated, I believe.
 
I have an AA 500 HFT and it's deadly accurate, but bear in mind it's a 12 fpe gun. I would choose an AA 500 for two reasons: 1. It has a power adjustment feature, 2. It shoots up to 20 fpe. Or you can choose the AA 510 because it's a repeater. I have no experience with the BSA, but it has a good reputation. The BSA is not regulated, I believe.
I believe the R10 SE is regulated. Do you know if the S510 has the match Lothar Walther barrel?
 
All R-10s are regulated. The MK1 regs had some issues but they are sorted now.

Both are nice guns, you’ll be happy with either. I prefer the balance on my R-10 over my s410. The AA guns are easier to work on and adjust.

The R-10 can do 20fpe in 177 but you need to check to see if it has a valve restrictor and you may need to order from Knibbs or eBay a larger TP. I’ve got an Ultra single shot that does 20fpe in .177 and likes 10g CPH and JSB heavies. It has a 4mm TP and heavy hammer.
 
I have an AA 500 HFT and it's deadly accurate, but bear in mind it's a 12 fpe gun. I would choose an AA 500 for two reasons: 1. It has a power adjustment feature, 2. It shoots up to 20 fpe. Or you can choose the AA 510 because it's a repeater. I have no experience with the BSA, but it has a good reputation. The BSA is not regulated, I believe.
How close are the AA 500HFT compared to the AA S510 Ultimate Sporter SE?