my 2 cents...
i was more or less on the same boat.. but was more comparing R34 to Sti or Evo 8/9 and XI as the samish price range, yet a lot newer and zero KM condition vs 10 year old 65,000km condition.
i found that newer cars like the Evo XI and Sti was a lot more refined tham R34 R to site in and drive, speically at low street speeds and the low rpm pick up is a lot better than GTR.
but in the end i brought GTR, cos i wanted and always loved them . not cos other cars were any bad.
i have not owned a Euro, but driven a friends M3 and was a really nice and easy car to drive, the interior materials, fit and finish was miles ahead i have to say.......
only time i have regretted buying the R, was when i recently drove a chipped Focus RS "new model"... it just was as RAW and race car like but a lot more chuckable and felt better than R. Again was driving on the speed limit and no above the limit.