"Does anybody know if the TM751 has better
RF reception than the CM15A" - YES -
*everything* has better RF reception than
CM15a.
I modified my CM15a and have emptied it -
(so it's only a multi-code transceiver) by
pulling the remainder of the internal
antenna outside, adding a longer antenna
tube - and inverting the antenna to improve
the RF performance (in the house-and a bit
outside - it's good now). You can see
photos of this simple mod at:
http://forums.accessx10.com/showthread.php? s=&threadid=88
Because it's cheap to do - I also have
added a TM751 on a housecode which is not
transceived by the CM15 - placed
strategically to receive just outside
sensors.
When I bought CM15a I also got the package
deal with various other modules etc. - so
returning it wan't a priority. I figured I
might as well use/abuse it - but rely on
Smarthome (because I could) to do the
clever stuff in my home.