FM RDS-TMC traffic routing on Garmin 2720?

[ehasler]

I'm thinking of upgrading my Garmin 2620 to the 2720 as it has a few features that would be useful to me, in particular the traffic routing facility, however I'm not sure how accurate and effective this is.

Has anyone here got any experience of using a satnav system with the FM RDS-TMC service, and is it any good?