I have some Proxxon tools and they are very nice, I'm sure the micro mill is as well, but put some emphasis on micro! IF it will handle the jobs you want to do and you are short on space go for it. The Shop Fox micro mill looks an awful lot like the Proxxon bench drill with the optional milling table. I have the bench drill and it is great for tiny things, not so much for anything larger. For not much more money there is the Harbor Freight Sieg X2 mill (wait for a sale and use one of the perennial 20% off coupons). I am very pleased with mine and it worked well out of the box. And it it's a good drill press as well.
+1 on the Harbor Freight mini-mill (#44991), especially if you use a 20% off coupon. If you can afford to go with a mini (instead of a micro), it's worth the cost differential. As for minis, though I generally prefer Grizzly, the HF mill has one distinct advantage - it has an R8 spindle (Grizzly has an MT3). The R8 means that any collets you buy for this mill can be used again on an "upgrade" machine. Almost no large mills use MT3.