I've had a MM3-pro for 3 years and it's a great machine. Rock solid, very accurate and no backlash. They are not cheap as you've found out, but you get what you pay for.
I mostly mill multi sided jewelry and other decorative small parts in wax and plastic, with the occasional AL part. I've cut a little stainless too and have yet to have a problem with the mill.
The only limitation I've found, is that I use a NSK spindle which has high rpm's but not a ton of torque so I can't make very deep cuts in AL without the spindle bogging down. The spindle is great for 99% of what I do, where I'm using .003" cutters, just not for metal and a 1/4" end mill. Get an appropriate spindle and you'll be very happy with it.