Well, so far so good. I've been using IMAP to access my Gmail for just short of a week now and haven't hit any real problems. Things were a bit slow at first as Thunderbird built the index of the folder contents, but once done, all seems ok.

The one thing that did annoy me for a while was Thunderbird wasn't checking all my Gmail folders/labels: it was only checking the Inbox.

I use a lot of filters on Gmail, so it's important this works. I know you can right click on each folder, go to properties and select "Check this folder for new messages", but this is tedious with a lot of folders. I also know I can setup client side filters, but once again, this becomes tedious on multiple computers.

So, back to our good friend Google for a quick search and I found what I was looking for. In order to get Thunderbird to check all IMAP folders for new mail, just add the following to your user.js file and restart:

user_pref("mail.check_all_imap_folders_for_new", true);

You can also do this directly in the Config Editor (Thunderbird 2.0 and later) by going to Edit -> Preferences -> Advanced -> Config Editor and searching for the above setting.

Now I have Thunderbird and Gmail working as I like it.