I will carry both my TRP and my Combat Commander. Either are no problem weight-wise with a good holster and belt, but there is definitely a difference with the Commander for stuff like the aforementioned sitting down, like in a vehicle. You wouldn't think 3/4" makes that much difference, but it does.
The big difference is between either of those two guns and my Springfield Micro-Compact. That thing just plain disappears in a Wild Bill concealment holster and is small enough that the all steel frame is not a big weight issue. I have had hesitancy to carry it on a regular basis in the past because it tended towards ~95% reliable, which is not good enough for me. I've been shooting it a LOT more over the last year though, with different types of ammo, and am finding it getting to 99% reliability, which is defensive carry-worthy for me.