I purchased mt 920 from Costco in December of 2007 with the 1 year map guarantee. Today I called TT about the maps, and they stated that the 1 year was supposed to be for European units only, but certain US units "accidentally" got the 1 year paperwork thrown in. That's what they told me today.
With that, the call went perfectly smooth. I had to make 2 calls in total. The first to get all of the info on how to get them what they needed and to inform me of the steps on the computer to take. The second call was made as I was instructed, after I had sent them the 2 pieces of proof they needed. They asked me to scan fax or send them the copies of the sales receipt and the map guarantee. They walked me through the steps necessary to do the install. There was no harshness or anything negative about the support call that i can think of other than what I've written at the bottom of this post. The phone was answered by a live person within 1 minute of finishing with the phonebot. These were the first calls ever made to TT, and I have to say their customer service from this experience, was great!
I am DLing the map right now. It's taken about an hour an ten minutes so far and It says it got another seventeen minutes to go.
The only negative I can report is that the first tech stated that the update would make my 920 function the same as a 930. The second tech stated that the maps would be the same and I would have IQ Routing, but not Advanced Lane Guidance. I don't know which one is right as I have not been reading the boards lately to educate myself as to what to expect.