Here's my first thoughts on the HTC Magic and Cupcake....
1. Email. I don't really use gmail directly, so went straight in and set up pop mail. Oh dear. The default mail client is appalling; just simple flaws like re-marking emails as read when a sent/receive is done - how did this get past Google's QA dept? It's actually unusable. Thankfully the k9 branch is much better - anyone using non-gmail email should switch to this. Still has bugs (eg it doesn't handle reply-to addresses properly for lists) but on the whole it's excellent.
2. On-screen keyboard is great; sometimes lags when the device is doing other stuff, but I can mostly type on it as fast as my old Kaiser.
3. Contacts/calendar sync - been trying to get funambol to work but with no success. Will have to play with goosync etch to get my outlook (non-exchange) stuff onto the device.
4. Satnav. I used to used tomtom on my Kaiser and having a replacement on the Magic is essential. Andnav2 has proven to be pretty useless so far - it spends far to long 'refactoring' the journey and kept thinking I was not on the right road. I'll see how it goes but I gather Copilot will be available next year so we'll see. Half the problem is the inherent flaw of having routing not done on the device itself, but perhaps that'll improve.
5. The device is good, and android makes a good fist of being a responsive and smooth OS. No complaints on that front but maybe 5 years with MS's shonky mobile OS has made me see it with rose-tinted glasses. Having said that I've seen the "sorry - app x has been waiting too long, would you like to force close it" dialog too many times.
6. Apps: loads of good ones out there. Market works well although the download bug (where downloading Apps never start) is a pain in the arse. Oh, and google's own Picasa upload App doesn't install due to a package signing problem. Shame on you Google, that's testing 101.
7. The browser is excellent - love the multi-windows and great rendering. The only flaw is that I can't read the mobile FT site because it reverts to the full site (which renders beautifully but is not quite as snappy as the mobile optimised one). Hardly a complaint!