My suspicion is that being comfortable with the tool is what’s most important for a good result. To test that I used seven different rip-cut backsaws aiming at a 1:7 angle, without marking it out, over the edge of 21 mm thick white oak.
The saws (from left to right in picture below) and their cut lines were:
Lie-Nielsen tapered dovetail saw: 10″, 15 ppi
Bad Axe Tool Works dovetail saw: 12″, 15 ppi
Pax 1776 dovetail saw: 12″, 15 ppi
Bad Axe Tool Works carcass saw: 14″, 14 ppi
Veritas carcass saw: 14″, 12 tpi, rake angle 10°
Lie-Nielsen tapered tenon saw: 16″, 11 ppi
Veritas tenon saw: 16″, 9 tpi, rake angle 14°
(rake angles, where not mentioned, were 0°)
The LN dovetail saw is the one I use for cutting dovetails, and I could immediately sense where I should go (though a little adjustment was required).
The Bad Axe dovetail saw was faster and had a very narrow kerf, while feeling different. The Pax dovetail saw I haven’t used for a long time and didn’t do well with.
I immediately lost control over the very aggressive Bad Axe carcass saw, while the Veritas one, and old friend, worked better albeit much more tardy.
Of the tenon saws, the LN is the one for everyday use, and though not small, it felt comfortable enough. The Veritas Tenon saw was the slowest of the lot. I suppose it must be because of the rake angle.
All in all: kerf and rake angle are probably very relevant to speed of cutting, and by definition blade length.
Wouldn’t the consequences of going astray also be a factor when weighing what saw to prefer? This picture below shows cuts for concealed mitred dovetails, and how too deep cuts would be quite visible along the joint line – which by definition always will leave room for improvements.
London, UK; Boston, MA