I say go for it. These bibs quickly turned in to my go-to. I have a pair of Castelli as well, but after a few centuries in each, I'm definitely more fond of these shorts. I'm not a world-class rider by any stretch, but I'm certainly aware of comfort. These bibs are the most comfortable pair of bibs/shorts I've owned. I believe they are tri-shorts; so, expect the cham to be a bit more toward the rear.
I've owned mine for most of this season and I've had no durability issues, nor have a experienced any chafing even after a 150 mile ride (60 of which was in the rain).
They're not perfect, but for the price, 5 stars!