Google does not really deliver much content (or my query sucks). Has anyone made the switch and can share the experience?
I haven't had any CFMX 6.1 apps to switch across, but Railo is definitely my CFML engine of choice.
Compatibility-wise, there is very unlikely to be any significant issues migrating from CFMX 6.1, and you can easily test this with the Express version - no installation required!
Railo can be stricter about certain aspects of CFML, so you might get a few errors if you exploit bugs/weaknesses with CF, but nothing really to worry about.
And, if you do get stuck on anything, the Railo mailing list is active with plenty of friendly helpful people who can help to get you going again.