I have not had any experience with brass sleeved cylinders..... But I work with two guys that once worked for a company (for several years each) that sleeves cylinders with brass. They are of the opinion that it is worse than a good stock cast or aluminum cylinder. And they would never use brass sleeved cylinders if they had a choice.
They are both in the restoration business now and if they need something sleeved they send it to a guy in NY and have stainless sleeves put in, they have never had any problems with stainless. Apparently the seal will sometimes stick in the the brass bore and even if you push on the pedal you don't stop. They say that is the worst part, not knowing if they will work when you need them. The brass ones also quite frequently leak. So even if they offer a lifetime guarantee, do you want to remove it to send it back for repair?
This is from the experience of two friends that have dealt with 100's of brass sleeved things, not my own experience, and I suggest you ask some more questions before you commit to brass sleeves.
