It was quoted on a builders materials list
when I look it up it looks to be a single skin product applied directly over the studwork
Do you house wrap / felt underneath ? - I can't find that detail
and at the horizontal joins I presume you would need blocking
It's just a decent quality exterior grade plywood. I think the only difference from generic exterior plywood is that they use a species other than fir for the outer layer.
You can do it single skin, but that'll be more complicated if you ever need to redo the siding. Or you can just use regular sheathing underneath. Materials-wise, if you assume the Breckenridge is $50/sheet and OSB is $10 (about what it costs us up in the hills around our way) then it doesn't cost a whole bunch more to do sheathing too. Labor may change that, though.
If you do single skin then I think you will need blocking at the edges, as you would with regular sheathing.