Hi there
If you're referring to the touch-screen RNS510, then yes, it does have traffic announcements / route planning around congestion. Can't say I'm particularly impressed by this functionality, however. Congestion info often seems out of date, it complains of there being queues when there aren't any and other times you're sitting there for 20 mins and it thinks the road's clear!
Re subscription - MAKE SURE YOU GET THE DISC. I got my GTi (brand spanking new) in March 08, didn't come with the sat nav disc. I gave up the will in getting if off the stealers (they were also miles away), ended up buying a fresh upgrade. Cost around 180 quid!! But I think I should be able to just hand this in every couple of years or so and get a free upgrade as a replacement.
hth.
M