I also run 35c tires as that is the max my bike can take. So far there have been very few cases when I was unhappy on it .. one time I got on some muddy rooty single track and wished for a bit more then. I have had some other times when the ride got a bit rough when the rocks got big, and I recently got some tire inserts so I could run really low pressures the next time I am on stuff like that. For pretty much everything else 35c is great, and you will have a bit more speed on the easy stuff so there is an upside.
Currently I have no plans for a dedicated gravel bike but who knows where I will be in a few years.