I tried it, but it really didn't work out for me. It's not your program, but Streets itself. When trying to add something quickly and on-the-fly while driving, it's impossible to read the text from a search on a 7" screen. Streets needs a large-font interface such as on iGuidance to make it work correctly.
I absolutely LOVE the planning features of Streets. When planning a cross-country trip (which I do non-stop), I can punch in exactly where I need to stop for fuel, where I need to stop for my required breaks, etc. When I put in the "Stop for" and "Depart At" times, I can be within 1hr of the projected time, even on a 2,500 mile trip. But, for the driving part (other than looking at the map), it just doesn't work out. So, for now, I use Streets to plan the entire trip, then use Garmin Mobile PC for each day's driving. At least with Mobile PC I can find and add a truckstop, rest area, etc as I need throughout the day.