I'm not sure what the "wrapped wire mod" you did is, but I had great success with the "18.5-inch reflector" mod.
I simply tapes an 18.5" length of insulated electrical wire (I think it was 12 gauge) alongside the CM15A's antenna, making the bottom of the wire even with the "elbow" at the bottom of the antenna. A few wraps of electrical tape holds the wire in place. There is no electrical connection to the CM15A's antenna, and it doesn't void the warranty, either.
For me, that seems to work incredibly well, and I get great coverage throughout my whole house. (I tested by using a PalmPad to activate a Chime module. The chime is loud enough to be heard throughout the house, so I could go room-to-room with the remote and test the RF receiver on the CM15A).
It took me only a few minutes to do the mod, and I was able to to remove the RR501 I had been using.