If the brand plans ahead for consumer assembly, then putting the bike together should be straightforward. I've seen both ways. Last year I unboxed a bike that clearly had been assembled with the idea that a shop mechanic with all the tools at hand would finalize the build. Since then the brand seems to have upped their game (and their pricing) to target consumer assembly a little bit better.

[quote[Also, there are many bike brands that offer a click-and-collect model (such as e.g. Trek or Felt) where you can order online and pick it up in the store, fully assembled Have you had any experience with ordering in this way? I guess that is the best of both worlds, judging from what I hear you all say? [/QUOTE]

Click and collect is a good model. There are also brands that partner with mobile services like Velofix and Beeline for the final assembly. I personally would be happy if the box contained just a frame and a pile of parts, but the typical customer is going to benefit from assembly by someone with some practice and some expertise.