Well, I have have different niggles:
- As said for product pages the Clip to PDF often does not work well
- If it works then you get a lot of white space in the margins (which you do not get with webarchives).
- Sometimes I want to get ride of side menues, etc
I guess often I just need to try different ways to capture the webpage…
Thanks for the links! 
Will need to try things out.