On the MTB side I've tried Magura, Shimano, Avid, Sram and Shigura (shimano/magura mix).
While the shigura takes the cake maguras are a close second, shimano comes after that and waaaaay behind are Avid and Sram. I had Sram Guide RE's, which should be powerful with four pots but they just kinda sucked. Low power and meh lever feel.
on the road I much prefer shimano. Road sram (older rival) was low power and meh lever feel. I don't know if it's piston ratios or what but I have never gotten any decent power out of any Sram hydro.