* slow (even with -o to stop it downloading the internet every time)
* incredibly verbose, in both configuration and output during builds
* inflexible (but I've not really looked into plugins or advanced configuration)
* opaque and thinly documented even for basic needs
I did a fair amount with ant a few years ago and found it a much more pleasant experience. Maven seems to me stereotypical "enterprisey" software: a mediocre, moderately complex solution to an extremely complex problem.