I'm not Whippet, but in my experience having the cutter measure and fit generally leads to a much better experience. My guess is that the reasons for this are that there is information gleaned from looking at a person, how they move and how they carry themselves, that isn't captured in a set of measurements but that can still be reflected by a good cutter during the cutting and fitting process. I also think that there is something to be said for pride of authorship. There are lots of ways to get a great suit, but for me having the cutter do the measuring and fitting is worth whatever hassle or extra cost might be involved, and that's based on a broad range of experiences. The rest of the making - the sewing and handwork - strike as something better sent to lower cost workers.