I've ridden a Jett and a Lithia, never a Ruby. The main difference is the padding. But I *did* sit differently on the two saddles, just because of the level of padding. So when I switched from the Lithia to the Jett, I had to make some minor fit tweaks.

Neither one was T-shaped enough for me in the 155 mm width, in a road position. The Jett is great in an upright position on my hybrid. I'm happy on my SI Turbomatic now.