I put some Deores on my BFe when I was building it a year ago purely because they were very very cheap, as in £80 for the pair! They are great. I buggered them up shortening the hoses but they are easy and fast to bleed and are very powerful.
I had Elixirs on my FS which I really liked when they were working properly however they needed bleeding every month or so and I got offered some cheap brand new SLXs from my mate so put them on. I think the Shimanos take a bit of getting used to as the power is very sudden but when you do they are good.
I don’t think the SLXs have more power than the Deores but they do have the funky ice-tec pads.