A lot of diverse opinions here and a lot of good points made. I'll share some of my thoughts with you. First, I've never been in the camp where I tried to keep up with technology at all costs. I hang out mainly in the Classic & Vintage area, so you can tell what sort of enthusiast I am. I don't dislike modern bikes and components, just the opposite, I appreciate them. But what I don't feel the need to do is take an older bike and try to make it into something it isn't.
If you are going to go, then I say go all the way. Just know that in a few short years, even that bike that was "state of the art" will be replaced by "newer and better". For example, mechanical disc brakes were all the rage until hydraulics came along.
Just some thoughts.