I have mixed feelings about WNTW (the US version). I feel like, most of the time, the advice is decent (although, short though I am, I will never wear pointy-toe shoes - I've never found a pair I thought was the least bit comfortable for my wide feet). And the women seem happy with the results.
And yet...I don't like the "ambush" tactics. And I do feel sometimes like Stacy and Clinton act like everyone should be spending lots of time paying attention to fashion trends and the like - and mostly, I just don't care that much. I just try to dress sensibly and comfortably for the occasion, personally (although I do wear makeup).
On SYTTD, I can sometimes understand the consultants' frustration. I remember one bride who was a professional cheerleader. The bride was interested in a classic dress, and her mother wanted her to be showing as much skin as possible. The poor girl was nearly in tears, right there in the salon. And the consultant was seriously annoyed with the mother and trying not to show it; I couldn't blame her at all for the comments made to the camera that the mother wasn't privy to. So again, mixed feelings.