The Minimig is great, period.
I'm happy to see it's selling well! I am a bit crazy about the Minimig: I bought SEVEN minimigs from Amigakit so I can have a minimig at home, other at my parent's home, other at my girlfriend's home, and other in my village home. I'm NOT rich, anyway: I just spent almost all my money in food and Minimigs for the last two years. And I am happy I did!
My aging A1200 can't compare to the Minimig in terms of reliability: SD cards full of ADF's and HDF's are just perfect for me.
I am also trying to make the minimig core work on my Altera DE1 board with ZENTEL Ram, just in case someone has got it to work... but the real Minimig worked out of the box, and with some home-made cases (and one shiny TheDaddy case), they are very good-looking too.
Thinking about the 4MB upgrade, but having to send the Minimig from Spain is a bit painfull...