In my relatively inexperienced opinion...
(I have owned a NS Oscar [not e61], an Isomac Millennium [e61] and had quite an in depth look at the same machines as you when buying my new one, but ended up with an Izzo Duetto [e61])
... there's not a lot of difference between these machines.
1) At the end of the day the shots will be very similar if not exactly the same (small differences in thermosyphon design may make tiny differences in the cup, but if it tuned well i'd be surprised if you'd notice).
2) Milk steaming might be a little different, slightly different user techniques will slightly favour one machine over the other, so figure out which one you find the most comfotable and easy to steam on.
3) The biggest difference is ergonomics and design. Pick the one you like the look and feel of the most.
For my money, I'd take the Technika Profi. Why? I like the design more than the others (although the Magica is very similar - I think it uses some of the same body parts), I like the steam leavers, I like the hinged water tank lid, and I like that the portfilters have nice handles.
They're the sort of differences that would make you choose one over the other between those 3 (and possibly other e61s) IMHO. You can't go wrong with any of them.
Best of luck!