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This is hard because I actually use MT on my personnal site and a few others. Here is the rule I use when deciding platforms.
A) What will it do?
B) Is that all it will ever do?
C) What is the most important feature for you?
Usually theres three questions help when I am weighing Nuke against XOOPS against Movable Type against B2 (etc).
If you know all you will ever have (or ever will have) is blog-centric data, then Movable Type will probably be your number 1 option. RSS, Collaborative Blogs, HTML page generation (for non google bots), and it's use of PERL instead of PHP all make it a better choice if (and only if) you are going to be doing just blogs.
The instant you start adding other things such as calendaring, profiles, and the all important forums, it starts becoming a lot trickier to decide what's best. I strongly encourage you in the planning stages to install a copy of each and see which one will better meet you and your user's needs. Sometimes the clients just like posting interface X over Y.
Give XOOPS a shake, and it might be just what you need! Good luck enjoy Xoops!