No, I wouldn't buy it again. I like a lot of things about it, but there are too many little niggles that drive me nuts. The battery life is the worst offence; I just can't get used to not being able to make it through daylight hours without a charge! My previous phone was a Nokia E71, which would comfortably last 3 days with moderate use (including downloading podcasts, using as a Joikuspot hotspot for my iPod touch, browsing, checking e-mails, a bit of GPS now and then....) The Desire is on red by 7pm, and that's without any GPS. Downloading a 20 minute podcast seems to wipe out 10% of the battery straight away!
I can't rely on the Desire next time I go to a festival, or go camping in the countryside. I'd have to keep it switched off, or carry a spare battery for every day out!
Other irritations: the keys on the QWERTY keyboard are too close together for me (I also have an iPod touch and the QWERTY keyboard on there is fine), especially the Menu key on the bottom left (can't remember precisely what the key is; my desire is away at the mo') which I keep catching when I'm typing - it takes me out of whatever I'm doing into a menu of some kind; very irritating when it happens 2 or 3 times per message.....
Funnily enough, I've just dropped my Desire and completely cracked the screen. Luckily, I have insurance, but rather than accept a duff, low spec replacement phone while mine is away being repaired I picked up a Nokia X6. In many ways the Desire is a superior phone to the X6 - Sense/Android is smooth and silky where Symbian is jerky and unlovely - but the X6's battery life is so much better than the Desire's. Tonight I used Ovi Maps to navigate to tiny little club tucked away in the middle of Leeds. It took me well over an hour to get there, but the X6's battery was barely grazed by the experience! I also listened to some music, took some pics, filmed 10 minutes of the headliners, texted a bit, popped on Facebook and had a brief argument with someone via their status updates, installed Joikuspot... My Desire would have been well over half-dead just from the drive. I've tested it out in the car over far shorter journeys and you can almost see the battery bar shrinking!
When my Desire (or its replacement) comes back I'm pretty sure I'm going to sell it on. Not sure I'll keep the X6 longterm, but whatever i get next will have to have a decent battery life. What's the point in having a phone you can't use?