I've built up 3 bikes. 1 conversion from downtube shifters, 2 complete builds.

I was surprise how long it took me because I was learning and fine tuning as I went along. If I do another one, I would not bother being so detailed in setting up just perfect. I would just throw everything on the frame and then tweak it. I found that tweaking along the way was pointless because something alway has to be moved and that would throw out the perfect alignments.

Be prepared to get your fork done at a bike shop. Cutting is better done with a good guide that only shops are likely to have. And don't get it cut until you have finished putting the whole thing together so you can play around with the handlebar height.

Most fiddly and frustrating for beginner builder like me was headset tensioning and back derailleur cable tensioning.