Ive got a Synapse 19 and Im considering a 40oz HydroFlak to up the insulation from my 32oz Nalgene. The only question I have is will it fit in the Synapse? The Nalgene at 32oz is a bit tight and it looks like the HyrdoFlask is a bit taller.
I saw in another thread how the 40oz would fit, but barely in a Synapse 25. Is the water bottle pocket deeper for the 25?