Me. 40mm stanchions don't really flex.True but trivial, depends on headtube lengths, fork model. and who want a mile of flexier stanchion and high BB, when an angle set would do the same.
I'm in the same boat as worship_mud and found it a great way to slacken my bike out (had it at 62* in the alps) without making the BB excessively low - I found the bike faster through rutted / rough / rooty sections with the BB at 13.75 vs. 13.50, and I know my frame isn't the only one that is already quite low out of the box. Using an angleset / angled cups alone to achieve the same thing would have left the bike too low and slower overall (I'm running -1* instead of -2*). Dropped the bar rise to compensate for the height and couldn't be happier.
There's definitely more than one way to skin the head angle cat and it's worth considering all the options and how they affect your own setup.