I have been shooting the Epic RC limbs with bamboo core for 4 years. Sorry, never tried the BM Carbon Extremes, but I have owned and shot the regular BM and BM Carbon limbs.
I have a very high opinion of the Epic RC limbs. I have a long DL and they pull very smooth all the way to 31". I've chronoed them, but I don't have the exact specs. They are posted somewhere here, but speeds where in the mid 180's with 10 grn per pound. Mostly, the limbs are very quiet. Once I got the Epic limbs I just didn't shoot the BM limbs. Gave them away. (found the specs, 181 to 183fps 10gpp)
The static tips are deeply recurved so the overall length of the bow is about 1.5" shorter than those with standard RC limbs. Makes them a bit easier to negotiate thick brush.
I've shot 1000's of arrows through these limbs and they been up to the Haul Road twice for caribou hunting. They are proving to be very durable.