I don't know about the worms....My tires are in varying widths, to some degree, and not consistent:

My 700x18 Vittoria Pro Team Open Chrono II are wonderful and smooth; thanks, txvintage.
My 700x23 Vittoria Rubino Race tires are great.

My 700x18 Panaracer Technova II's were horribly hard and not at all fun.

My 700x23 Vredestein Ricorso's were, as cudak888 warned me, hard as rocks.

My 700x18 Hutchinson Fusion II is hard as a rock, looks fast, but not all fun.
My 700x23 Hutchiinson Fusion II is great.
My 700x23 Hutchinson Equinox are good for the price.
My 700x23 Hutcinson Profil-U HP25's are the best relaxed tire I've ever had.

My 700x20 Pro Race 2's are fine, but not as smooth as they could be and not for bumps.
My 700x23 Pro Race 2's are great, and I'll buy more when they wear out.

I think you can still get 700x20's in Pro Race 3's, I believe. There will always be a market for skinnies.

I read somewhere that Michelin tested rolling resistance and the 23's roll as easy as the 18's used to. I don't know. I can corner with more confidence on my Vittorias than anything, regardless of size. I've tried several of the tires on the same wheelsets, and my preference is Vittoria, overall.

Some of the tires look a lot bigger than others, and I'd be willing to bet actually are, regardless of size rating.

As for wheels, well, I don't know about them, either. My nicest set are old and heavy, but aero and 16 spoke count (Ventos) but the best set I ever rode on were older school Wolber SC Alpines with 36 spokes.

My racing friends are all about aero. One of them had me run my Kestrel up to 20 mph and then coast, to try and show me the aero difference. With an aero set of wheels and 700x19's, the bike "held speed" about 15seconds longer than with my training wheelset. When I added the disc cover on the back wheel, it held speed 40 seconds longer over 3 runs. We did this over and over, and I admit a difference. Then we had beer.