Once you get into this $ territory in "traditional" machines, IMO they are all great machines (I'm talking traditional machines, not specced up Breviiles etc) and the limiting factor in producing a ripper brew would be your technique and ingredients (assuming your grinder is semi decent, dont forget the grinder has a big impact). Almost all should be decent quality.
The rest is mostly what you find appealing in looks and layout. Many machines look almost the same (say most E61s), but its the small details that define them.
Best bet would be to go to a sponsor or two and see and feel them in the flesh and preferably have a play.