This is a great app, especially if you have a lot of mail (I have 8GB which is way too much for Mail, Thunderbird, etc). Love having Gmail separate from the browser and the convenience functions (Growl notifications, etc.) are worth the price. Try Fluid if you don't mind going without this functionality.

Seriously invaluable if you have multiple Gmail accounts. Great stuff.

Beta version 2.0 beta 2 known issues:
- "Safari Ad Block" and "SafariBlock" are not compatible with newer WebKits and cause Mailplane to crash. Workaround: Uninstall these InputManagers or enable use "System WebKit" in advanced preferences (req. Safari 3.1.1 or newer).
- Strange file extension (.doc.dot) in MS Office documents. This is caused by MS Office 2008. See this Apple Support thread for more information. Workaround: Rename the file.
- Using the mouse to insert a contact from the contact autocompletion doesn't work. Workaround: Use TAB or ENTER key to select the contact.

For those using the beta version, there's a new version out:
2.0 beta 2 (734)
"Important update for all users!

Gmail is pushing out a new Gmail 2 version, this may lead to these problems:
external links and downloads do not work
The Mail menu doesn't work correctly
compose new in separate window doesn't work

New: Faster loading

Thanks to Google, Gmail loads much faster! Account switching, new message windows, and initial startup are much zippier! "

Version 1.60 (and previous too iirc), gets quite often stuck when sending a big attachment (ie: over 10MB). Opera works much better for this.

I'm on the beta. Regarding the pricing, yes, I must admit I find it steep, too. When they are out of beta I'll still buy a license though, simply because I tried all the gmail 'enhancers' out there (including on the PC) and mailplane is the only that work 90% the way I'd like gmail to work.

Bottom line is that google crippled gmail multi-account behavior on purpose - if you have 8 accounts or more using their 'google for your domain' program you must logout and login again each time you want to check a different account and it takes fooorrreeevvverrr to do do so, AND you can't know how many mails you got in each inbox. Even with apps like netvibes you still can't switch between accounts easily. But with mailplane you just doubleclick your account name and voila. I monitor dozens of accounts accross domains and this app saves me a LOT of grief.

Great app and friendly developer.

It is a great application for people with many active gmail accounts, however if you only have the one account then, as suggested, IMAP your gmail and save your money.

Nice App and I was considering buying it for my girlfriend. But with Gmail's IMAP support I willl spend the money on drinks and set her up Apple Mail.

Forget wasting $25, get IMAP for Gmail and use it in Mail
https://mail.google.com/support/bin/answer.py?answer=75725