This is the setup I use too, but the main downside of it is that sending a message from within Gmail, as an account other than the main account you're logged in as, reveals your main account email address.
For example, if you're logged in as somebody@gmail.com, but send the message as evilperson@gmail.com, you'll reveal somebody@gmail.com to the recipient. In fact, Outlook proudly displays this address by stating "From: evilperson@gmail.com on behalf of somebody@gmail.com". I think you can also easily get this info from the mail headers from most web-based clients.
Maybe this isn't an issue for most folks, but it can create havoc with your filters if folks start replying to an address you had hoped to keep hidden from them.
For example, if you're logged in as somebody@gmail.com, but send the message as evilperson@gmail.com, you'll reveal somebody@gmail.com to the recipient. In fact, Outlook proudly displays this address by stating "From: evilperson@gmail.com on behalf of somebody@gmail.com". I think you can also easily get this info from the mail headers from most web-based clients.
Maybe this isn't an issue for most folks, but it can create havoc with your filters if folks start replying to an address you had hoped to keep hidden from them.