The nice thing about the DASH is that it does a LIVE lookup through it's GPRS connection to yahoo search, and yahoo local for any information. Meaning, the "POI" information is the most current and hopefully, the most complete. Problem with this solution though is that WITHOUT the GPRS connection (or the wifi connection is also has) there is basically NO POI information on the device.
The traffic data does seem to be getting better though, but I haven't found it better than MSFT live traffic or google maps traffic on a smartphone.
Time will tell if their connected network effect bears fruit.
Plus, it is pretty expensive at $400 PLUS minimum $120 a year for the service fees.
For the money, i'd find a nice garmin nuvi (I still think they have the best routing and features) or a higher end model if you want to have traffic added.