I passed an inspection by the state and a pre inspection by a professional electrician. I'm not an electrician but specifically asked this question since I always wire with 12 gauge.
I see what you are saying, you can always suck more than 15 amps through a 15 amp outlet with the proper splitters and power strips. The outlet could be asked to pass more than 15 amps.
I think you folks are right. It is more logical to match the outlet rating to the CB rating.
Highbeam, I was wrong, just spent an hour reading about this.
The 15 amp and 20 amp receptacles have the exact same capacity so don't feel your system might of benefited from using the 20 amp outlets.
The only difference is in the slot configuration, the reason for the 2 different ratings is that that the 20 amp outlets can not be used on 15 amp circuits, so if you see a 20 amp outlet you can be assured it's a twenty amp circuit and you could plug that specific 20 amp cord in. (been around for a while and have yet to see one of those 20 amp male cord ends)
I learned that as long as there is more than one receptacle on the 20 amp circuit it's ok to use 15 amp outlet, so a typical duplex receptacle would be considered more than one and ok
The exception here is that it appears that kitchens, baths and laundry areas would still need the 20 amp slot configuration, not 100% sure about this though.
That way of doing things was a very good idea back when the receptacles had simple push in connections.
Today, the screw terminals, and bridge connectors, on the 15 amp receptacles can handle the 20 amp load. And would in my opinion, provide a better connection than a wire nut.
The 15 amp limitation is on the female plug in the receptacle.
If the feed through restricted the current flow, then 15 amp receptacles would never be allowed to be used on 20 amp circuits, because the bridge connector would become a fuse.
What your saying about the 15 amp limit being just related to neutral slot configuration, is what I just spent an hour learning about and finally makes sense to me.
Could never figure out why on the 15 amp GFI's that it said on them that they were rated for 20 amp feed-thru or load. Now I know it has nothing to do with the devices capacity as they are exactly the same, but more about protecting a 15 amp circuit from plugging in a 20 amp cord.
As far as your other point about using a regular duplex receptacle for feed through, I'm still learning about that but appears that is is allowed as long as its only 110 volt and not multi circuits in the box?
Though it's allowed I don't think it's a "better" connection than a wire-nut/pigtail since there is apparently more resistance through the receptacle. It's just a tiny amount but could become an issue if gone through 10 outlets like that. I'm still researching this.
Back to the 20 vs 15A outlets and GFI's now I Know the 20's just cost more and offer zero added capacity, especially the GFI's, those can be considerably more $$$
So the bottom line is, on 15 amp circuits you must use 15 amp outlets but on 20 amp circuits you can use 15 or 20 amp outlets
JB.