Plugin Pros and Cons

Since it's now possible (well, it has been for some time) to use XMPP to connect to Facebook Chat, this doc lists out the differences between the two methods.

Reasons to use the plugin

• Larger buddy images
• Works behind proxies
• Supports multi-user group chats
• Inbox notifications
• Status message support
• Works without a FB username or without clicking a javascript link (important if you're using a screenreader)
• View profile info when using Get Info on a buddy
• View the messages sent from the website in the conversation

Reasons to not use the plugin

• Less stable
• More prone to break since it relies on scraping the FB website
• Can log you out of the website while you're using it
• Logging in too many times triggers captcha's which don't work