Honestly for what I do (and many of you I guess), I'm sticking with 3G. Slacker is doing OK and the Map is rendering fine. The browser is very basic and using my phone is way more reliable since the browser light years better and everything is synced.
Edit: Unless the new SIM card is Canadian and I won't have to deal with dropping signals all the time. But in that case, is it going to work in the US?