JS!
Your post caught my eye ... and whereas I don't usually put up pics, I thought you might enjoy! So ... FLAT, and have played the same configuration and set up for close to the past 30 years! Buddy influenced from about 1973, in both set up, brand, and cymbal angle. These are my 1967/68 Fibes Buddy Rich's, but regardless of what set I'm gigging, the cymbal angle remains the same. I work primarily with a Frank Sinatra Show .. but .. I also work with a smooth jazz quartet, and a 6 piece "corporate gig" band that plays all the dance stuff from the 60's through today. Only reason I make mention of all that is I don't alter the cymbal set up/angle. Always ... FLAT. Works for me! And it goes without saying that it's completely subjective to personal taste!
Tommyp