I first come across WordPress MU about just over a month ago.
Its hard going yes,lucky for me I had a good admin at my reseller site who set up the server side and things, but even then there was a lot of things to learn,but I searched the forum and Google 24/7, I still have a lot to learn, but the forum members have been brilliant in their replies and help, if you ask a sensible question you will get a sensible answer, but if you ask a silly question, you'll be Googling all day.My site is now set up I'm pleased with it, I have added things from different themes to make a reasonable looking site, I have experimented with different things, if they did not work I tried something else, I even have a shout box working on my site.
So remember all you that are about to give up on Wordpress MU, don't. Patience is a virtue, and I'd like to say thanks forum members, without this forum I don't think I could have managed.