How do these geometries compare? Any real difference?

Head tube angle is 69 for salsa and 70.5 for boris. Salsa is a bit more modern I’d say and will handle better when you get pointed downhill. I have a 68.5 on my bike and I wouldn’t want to go any steeper than 69 I’d say. They will both work but it depends on what you are used to etc. I’d recommend riding a few different bikes from the local shops if you can get an idea what the different geometries feel like