To me, no. They feel extremely comfortable. You are aware of them for the first few minutes, maybe up to an hour if it's your first time, but they just feel so natural since they provide total natural mobility to your feet and all of its tiny bones. I wore them on a job yesterday while doing some networking in a new office, and after 11 hours on my feet, I had no pain. The same stint on Friday wearing a pair of good ol' steel toes had me crying for bed by the end of the day.
The only odd thing about the feeling is having your toes encompassed, but that sensation fades fast when you can feel your individual toes flex as you walk/run.
I wear them barefoot for short durations, but have Injinji toe socks for any longer periods, mainly just to deal with sweat.
I've never worn mine with socks. Do they feel the same or are they a bit tighter?