Yes, you are correct about the shape of the loops - they just need to be the same shape (and size) and be symmetrical relative to the axis of the mast. However, the coupler location will be different than what is stated in the Array Solutions manual. The manual specifies that the base of each loop needs to be truly horizontal. When using a loop with the bases having an upward slope, the couplers need to be located closer to the mast.
The coupler location can be determined by running the antenna model (you can find a copy in the files section of the Shared Apex Loop Yahoo group : https://groups.yahoo.com/neo/groups/sharedapexloop/info
). Or, you can post your desired dimensions, and I'll be glad to run the model for you.
P.S. The Hamvention 2014 Antenna Forum Shared Apex Loop presentation has a short discussion about the loop shape and is located at this URL: http://youtu.be/i46kR0pynFw
I was just watching your YouTube video, and had a question. I'd like to install on the side of a hill in my back yard. In your video, you indicate the shape of the loops is unimportant, as long as they're all the same. So, do you see any issues if I use more of a pennant shape (I.e. No flat bottom, but rather an elevated outside corner to the loops)?