I've used them and have mixed feelings on them.
I'm not a huge fan of DSC wireless to begin with (first the 900 Mhz problem, then major issues with the 433 Mhz reliability) so I might be very biased.....it's pretty bad when the company's engineers tell you that their wireless product was rushed to market with major bugs and issues, but that may be me. I can remember taking scores of DSC wireless and tossing it because it simply stopped working after a low or dead battery.
To me, unless it's the only way I'd get a retrofit takeover project, it would not be my first choice. It's going to increase the system's complexity by having technically 2 ESN's, with only a record of 1 within the system. It'll also increase the failure points and possible latency (though marginal) of the system itself.
IMHO, the price of the board is attractive compared to replacing devices, however I believe it's prolonging the obvious in smaller installs. Compared to the price of a small amount of equipment vs. the M1 and related hardware....to replace your wireless outright with Honeywell, it can be done for less than $600 total and be a direct integration, with a single common part to service.
If you had 30-60 points of wireless, sure, but as a pro, it'd only be for takeover purposes and not a first choice. I'd also make a migration plan to get away from 3rd party products and stay with a single platform wherever possible.
