I have Nextel and although I recently upgraded phones I didn't get one with bluetooth because there wasn't one available under $300 and that's just not worth it for me. Not to mention I've read somewhere that the TomTom cannot connect to Plus via Nextel's (Motorola) hardware or system. It just seemed like a huge headache to me just for traffic. I'll never download maps, POIs, or voices from TomTom (where you're paying not only for mobile service but also paying TomTom for the item you're downloading).
Getting traffic updates via home would be perfect for me because I would just plan my route before I left home, get the traffic info I can expect, etc. Also, there are a LOT better wireless plans (broadband wi-fi) for notebook computers than for phones. It would be much quicker and cheaper to get the traffic info via the internet and then sync it over to the TomTom via Home.