I have the Dash and no complaints at all. As far as wifi goes, you can use it with your own home network and any free hotspot (libraries, Panera Bread, etc...). Certain hotspots like T-mobile (Starbucks-next 5yr anyway...FedEx/Kinkos and Borders) and AT&T (Starbucks, Barnes&Noble) charge. One loophole with Starbucks is that if you have a Starbucks card, you receive 2hrs or hotspots usage a day free

It's a promo under AT&T that rolled out this spring. Also, if you have AT&T dsl, you can access any AT&T hotspot for free.
One other alternative is Boingo. They offer a plan for $7/mo for handheld devices for their hotspot locales.