I carry a Glock 26 in a Kydex and I know it's there, so there's a fallacy in thinking smaller handguns = no notice, but I'm never uncomfortable with it. If someone has problems carrying any firearm concealed, he's doing wrong somehow. Either the wrong firearm for the lifestyle or the wrong gear to tote it around.
In addition to the Glock, I've carried a full size 1911, a snubbie .38, and a Ruger P95. Never had a problem with any of them. But I also have a different gear setup/carry style for each firearm because each one fits differently on my bod and requires a specific rig set up to make it more comfortable.
You should never be uncomfortable carrying. With the right rig, I'd bet you won't notice a Ruger. Of course, it's like trying new food; if you've already made up your mind that it won't work, you'll probably find something wrong with every option you try.