Defy is small (107 x 59 x 13 mm) compared to many smartphones, such as Samsung Galaxy S (122 x 64 x 9.9-14 mm) and thus fits nicely into your pocket. The 3.7" screen is also very sharp and clear with approximately 265 dots per inch (10.43 dots/mm)! What I was especially impressed by, however, was the fact that Motorola has made Defy a very durable phone. It is water, shock, dust and scratch resistant, as proven by these YouTube videos where the phone is abused but just keeps on going. Also, Engadget couldn't really think of any downsides in this phone, save for the Motoblur UI, which my version of the phone didn't even have in the first place. My version also does have Android 2.2.
As this is my first Android phone I cannot really tell the difference to any other similar phones, but to me the phone feels fast and responsive, although I have had to reboot it once when it for some reason became very sluggish. Other than that playing Angry Birds, for example, has been a pleasure. Only few levels in Angry Birds Rio, for example, have so much stuff around them at first that the game slows down a little, but that is fixed after you slingshot the first bird out and manage to destroy anything. :)
Multiple home screens is also a nice feature. I have my calendar and SMS information along with the most used shortcuts in the first, a Facebook and a Twitter widget in the other, etc. The pull-down menu at the top of the screen is nice and features many kinds of announcements (mostly just for new email and newly installed programs). In the app menu I would like to sort my installed programs into different folders but that doesn't seem to be possible, although there's probably an app for that too in the Android Market, and using the different home screens for different program categories has been working for me so far.
As nice surprises for me the phone also features a radio (once you connect any headphones to it using a standard 3.5 mm plug) and a magnetometer, which basically translates to an electronic compass. The phone also has a GPS receiver so it knows its location and orientation, allowing you to use cool apps such as the Google Sky Map which is basically a virtual planetarium where you can point your phone into the sky (or the ground for that matter) and it tells you what stars and planets are there in that direction. The phone also has WIFI so you can enjoy fast internet connections wherever you have a WIFI access point.
The virtual keyboard takes a little practice but I guess that's inevitable with the first virtual keyboard you have ever used. When you get used to it it's easy and has been called better than the virtual keyboard in other Android smartphones. Swype is also a neat method for entering text -- if nothing else then it at least provides amusing guesses. ;) A little drawback is that if you want to write an SMS message with the phone in a horizontal orientation (to get a larger keyboard), you don't see the amount of characters used until you exit the writing mode, so you risk writing too long messages and having to shorten them before sending (if you want to fit it all into one message). Even when using the phone in a vertical orientation, you need to write something like 40 to 50 characters until the area for the text is made taller and the character count becomes visible.
All this being said, so far I have been very happy with my phone and can recommend it for anyone looking to buy a new Android phone. :) It has been made durable so I would expect Defy to last more than the two or three years which has been the life time for my previous two Nokia phones.