The Sense UI is very well integrated with social networking as well - primarily Facebook, Twitter and Flickr. At the bottom of each person's contact details there's an option to slide across to updates and events, which gives you the chance to link the contact to a Facebook friend. The phone will actually suggest friends with similar names on your Facebook and contact list so you can easily link the two together.
This means status updates appear on the person's contact details when scrolling through the list, as well as their Facebook profile picture (which also pops up when you call them too). While the person's birthday is popped into the details as well (should you want it) the same information isn't put into the calendar, which would have been amazingly handy.
Slide a bit further along the bottom (where you can also see all texts, emails and calls you've exchanged with that person) and you can see pictures of that person downloaded from their Flickr and Facebook accounts, should they have allowed others to see them.
Downloading the pictures to the phone, especially over a 3G connection, does take a few seconds, but after that you can flick through them as merrily as you can on a gallery on the HTC Hero itself, which is utterly brilliant.
As part of the Sense UI, you can also have a strip of favourite contacts, with the Rolodex style of interaction and a picture of them as well.
This makes interacting with your favourite people, be it via calling, texting or emailing, super easy and even better than it is on the likes of the HTC Touch Diamond2.
The dialler, accessed by pressing the call button, brings up a small preview screen of your contact list as well as the number pad. This means you can type someone's name in the same way you would in predictive text mode, and their name will pop to the top of the screen. If there's nobody in the phone book with that combination of letters, the phone will just switch to the number you're trying to enter.
We tried to import our contacts onto the phone, but the HTC Hero was having none of it. Every time we did so, it decided to simply add six names to the phone, despite promising 211. It also wouldn't let us copy across single names, which we can only put down to a highly annoying bug.
Were it not for the fact we have all our contacts backed up to Google, most of the functionality on the HTC Hero we wouldn't have been able to test.
UPDATE: This problem is now fixed with the firmware update - the whole import process runs much more smoothly. However, we're still waiting for Google to sort out the contacts book - we ended up with 96 blank spaces when we synchronised thanks to a multitude of unassigned email addresses.
Call quality is excellent as well, with the lip at the bottom of the device curving the microphone closer to the mouth. We're well aware that such style features are mostly redundant in today's ultra-powerful microphone world, with noise cancelling and whatnot meaning you could have the sensor in your ear and still be heard perfectly well.
Still, it made it feel nicer when cradling the phone close to your head, and the overall reception was pleasing, with 3G very rarely dropping out on us.
We found bizarrely that cradling the phone between shoulder and face isn't a good idea, as others frequently couldn't hear us when we were trying to multi-task, so we'd advise you give that a miss.