Not.
Pros:
- Better looking interface
- Slightly more user-friendly interface
Cons:
- Time
Or to put it in plain English, the MovableType upgrade takes more time than it’s worth. Perhaps there are some great things about the upgrade that I’m missing because I don’t use them, but as far as I can see it’s almost the exact same system with a new look and feel, and a new look and feel isn’t worth the upgrade process. If it were a one-click type of deal and took five minutes to do the upgrade I’d say sure, might as well do it, but it’s a bit more involved than that, and at the end of it all you look at it and say “Well, it looks better, but does anything really work differently in a way that will substantially improve the quality of my blog or the process of administering it?” Not that I can see.
