I recently switched my smartphone from a Blackberry Storm to the Motorola Droid. I was not planning to as we went in to get my wife a new phone, but there was this two for one sale, and you know how it is.
Anyway, I loved my Blackberry, so I was hesitant to change. The Blackberry did so many cool things, and allowed me to stay organized and productive with calendars, task lists, email, and so on. The sales person at the Verizon store said that the Droid would be great if I liked using apps. I was concerned that I was trading the grownup productivity of my Blackberry for a phone that would have a lot of games, but nothing more.
But, I made the jump, because I could return it in 30 days (ah, those cleaver marketers). And I have to say, at first I was often frustrated with the Droid. Simple things that I knew very well how to do on the Storm were often very difficult to figure out on the Droid. Everything from setting up the sound profiles, even finding where you set up the profiles, setting up email accounts, and syncing were all different.
However, over time I did find a lot of cool apps, not just gimmicky games or time wasters, but some that really help me out. For example, I found I could connect my Droid to the wireless network at home, even surf shared document resources on my desktop from my phone, and print to my shared printer from the phone. Wow.
When I travel I liked using the Storm and the VZ Navigator, the GPS service on Verizon for the Blackberry. However, it was an extra cost of $10 a month to turn it on. With the Droid, it uses the Google Map system and does not require any extra monthly charge to use. Combined with the browser capability, it is very powerful to locate a store, or even a contact in your address book, and have it take you there. It was a bit strange when I asked it to navigate to my home, and when I arrived it showed me a picture of my apartment building from the street. No kidding.
I still would not trust this GPS for more off-road travel such as camping or working away from civilization. You need features that the phone system does not do. Go here to see recommended handheld GPS units.  But for citified work, the Droid is working well. It has been more than a month, and I did not take it back.