For the better part of a month now I have been shooting with both of these cameras. I like them both, but they have different strengths and weaknesses. So here is my basic comparison from the field, personal opinion, not formal controlled tests.
1. Great retro design. It has the appeal that us older photographers can love because it is designed like cameras of the past.
2. Hybrid viewfinder is fantastic. It offers the best of both worlds with EVF and OVF.
3. Image Quality is excellent at all ISO settings up through 6400.
4. Controls are well designed, and much improved over the X100.
5. I only have the 35mm f1.4 lens and it is superb. Those with the other lenses seem equally satisfied.
6. With an adapter it can be used with other lenses, but I have not done much with this yet, though i intend to.
NEX 7 strengths:
1. Smaller than the XPro. I consider this a plus.
2. 24 megapixels gives fine resolution of detail.
3. The Peaking feature makes use of adapted lenses a joy, and focus is precise with this feature.
4. Available lenses are good quality and reasonably priced (with the exception of the Zeiss 24 on the price point!)
5. The tilt LCD is very handy for from the waist and above the head shots. This is important to me for street shooting.
6. The controls are well arranged and GREATLY improved over previous NEX versions.
7. The NEX focuses faster than the XPro1, but it has a problem with purple fringing with wide angle adapted lenses.
Here are some recent samples from the two cameras, but they are not intended for direct scientific comparison because the circumstances and post processing vary too much for that.
NEX7 with adapted Pentax 77mm Limited lens using focus peaking. ISO 1600
NEX7 with 21mm Voitlander lens. ISO 1600
XPro1 with 35mm lens at f1.4. ISO 6400
XPro1 with 35mm at the All State Girls Chorus (my daughter is in this). At f2.8 from the balcony ISO 800.
In the original jpeg all the girls faces can be clearly seen and identified at 100%.
If anyone else has input about the comparison between these two cameras chime in here.