I should have explained better
I understand ETT, and have always used it to determine if a bike is the right size.
Reach is the distance from the centre of the bb, projected vertically to the top of the head tube, and its that horizontal distance.
This should be a good indicator for size, as the seat tube angle doesn't matter in that case, whereas it does for ETT.
Anyhow. With a similar setup, and a longer reach, why doss the sultan feel smaller?
This is basically because I'm looking to buy a salsa spearfish, and the ETT is the same as my 5spot, and the reach is slightly longer. So should be a good fit, however the reach is shorter than the sultan... So... Is it a 29er thing?!