IMO, it is. The appearance of it is quite old, and there are nowhere near as many features as readily available or user-friendly on Firefox as there is on Internet Explorer. Plus, every time I use Firefox (usually once every month or two, when youtube is having yet another bug with IE), it makes me wait 5 minutes for another useless update.
1. You can customize the Firefox look with themes (I believe there's even an IE theme if you're drawn to that theme), something you don't have with IE. Plus you can add additional features as Add-ons.
2. IE, while it has improved in the past few years, still uses a quite inferior and out-of-date rendering engine. Browsers like Firefox have better performance and security in the long run compared to IE.
3. You are never required to install updates on Firefox. If you don't want to wait the short amount of time for the updates to install automatically (which for the most part will actually be LESS than 5 minutes), change the option to "Ask me what I want to do" in the Updates tab on the Advanced section of the Options dialog.