When I first started doing this, I don't think getting a domain name was tha simple (of course, I didn't research it much). As for the outgoing mail, I can set my mailer to have it come from the pobox account. Plus, I really like the things they do with SPAM filtering.
If I were starting now, and a domain I wanted were available, I might well do as you suggest
Cheers.
It was probably more expensive, but was never too hard to get a domain. Getting email associated with it has become much easier of late.
I like the Gmail Apps solution because it includes all the anti-malware/spam/virii scanning as part of the setup. And it is still all free. Setting the from address is something that is highly dependant on the system where you are sending from, so if you are sending from a web-based solution that is often not available.
For someone starting today I would recommend either picking one of the webmail providers and just using that domain or getting your own domain name and Gmail hosted for the best price/performance combination.