It might be interesting to do it the other way around - to have professional fitting done for you on all of 'em. Then, compare how different your critical measurements are. If you're still looking at 1, 2, or 3mm difference, well chalk that up to your adaptability - after all, you do have different TT, diff angles, not to mention rakes.

I bet that even if you do this, they will all still feel different.

I had an somewhat similar discussion with my orthopod who also has written for Rivendell in the past. He told me (paraphrasing) "you can discuss theory about this and come some conclusion, but you may be overthinking it - the best thing you can do is to have the bike professionally fit to you."