Yeah, 100 mil spaced square header pins are pretty standard in size, about 25 mils, square. This is actually lots thinner than say leads on TO220 and whatnot. Personally, I have only had problems with breadboards when stuffing in such things as large leads.
If breadboard has problem with 25 mil square pins, buy a better breadboard. This size pin is staple for breadboarding/prototyping in my shop. My breadboards all handle standard pin header and will still contact IC legs, no problem. I try to avoid stuffing anything bigger than 25 mils, though. The larger and flat component leads will often be bent, or twisted 90 degree, to go in sideways.
One con is breadboard space. Oftentimes, the adapter is going to cover some of the available holes. On my SMD adapters I make habit to use extra long header pins sticking up thru the pcb. I usually use wire wrap to jumper connection on the breadboard. Even if you do not, the long pins sticking up give you somewhere to clip a probe. And eventually, one day you will find a need for more spot to make multiple connections. Same thing with any temporary pin header cable I might make for prototyping. Long pins sticking out both directions. This way, when the cable is plugged into programmer/logic analyzer, etc, I can clip scope probes or add more wire wrap connections on that end, too.