I run Revit on a dual-Xeon at work (Nvidia Quadro 4000, 32GB, SSD) Core i7's at home. Max works better on Xeons because it addresses multiple cores and the Xeon has more, Revit 2014 doesn't (yet).
In Austin we moved from Dell to Boxx Technologies systems (they were about a half mile from our office at the time) and they seemed to run much better because they were made for the higher end work and cheaper than the higher end Dell computers with much less crap software loaded on them. You can get either Core i7 or Xeon with Boxx.