-eeeeee… if you’re in a group ride, it doesn’t matter. Unless there is crosswind…where you’ll see a huge difference.
-28mm tires can be aero with wide rims. 23c with the right rim will be faster, and 23c with the wrong rim will be slower.
-Disc brakes - on a traditional setup the disc version will be slower. Newer setups leverage hydraulics cable routing capabilities and fork design freedom. With the cables better hidden and fork blades moved away from the tire, disc is neutral or better than rim. If you think about it, a rim brake is an awful shape for controlling air. .
-Ironically, the slower you are, the more time you save with aero. You’re looking at 4-5% energy savings with the right wheels. The (.5) right bars, helmet, outfit, and (.5) frame net your about the same.
The fact of the matter is that a fancy aero wheelset from the right vendor costs about the same as a non-aero wheelset. You have to think about the incremental cost, not the cost if you’re buying wheels.
$250 DT Swiss 350 hubs + $50 spokes + $100 Swiss pinned rims = $400
Aftermarket alloy 32mm deep wheelset = $400 (469gbp shipped - $220gbp if you settle for the noisy hubs and ugly graphics - e1800) (Swiss ER1600 DT Swiss ER 1600 Spline 32 Disc Road Wheelset - 700c | Merlin Cycles )
Proper “aero” wheelset - for $700 ($523 gbp shipped) you can have proper “aero” wheelset that’s a lot more durable and looks cool
…so the delta is about $300 if you’re buying aftermarket wheels anyway.
Have a look here if you can read German or data… these are all iterations of basically the same family (with a few odd balls) - an ‘ugly’ (to the air), well shaped bad dimensions, medium, through “perfect as it gets” with the same tire, the same-ish spokes, three versions of the same hub family (or similar), and rim types (shallow ugly, shallow well shaped, mid-ugly, mid-well mid-shape, mid-nicely shaped, nicely shaped wide rim)
https://uqxbtrpjk4flbkpvuskzr5dsoi--www-radsport-rennrad-de.translate.goog/test-teile/laufraeder-windkanal-praxistest/
https://uqxbtrpjk4flbkpvuskzr5dsoi--www-radsport-rennrad-de.translate.goog/test-technik/dt-swiss-arc-1100-dicut-test/
So 4w @ 21.5mph (single wheel, that includes wind, so this is a LOW speed) best to worst (inc the 65mm deep wheel) on wheels that were hampered by the rim brake width for the tire they had on there.
**Note that none of these had round spokes, so that’s another 1-3w over generally good wheels to perfect.
These are all $500+ wheels (street), a $250 Fulcrum 7 (a very basic quality realistic wheelset) has been shown to be about 2w slower than the Mavic in the wind, supporting the spoke thing. You’re looking at 7w difference (F&R) for fancy wheels v fancy or 10w fancy v basic. That’s $250 for the first 3w, $250 for the second 3w, and ~$250-1500 for the remaining 1-2w. The helmet is $300 for 5w. Narrower aero road bars $200 for 15w ( http://www.aeroweenie.com/assets/img/data/tour-road-bars.png ) . If you go full TT, you can buy 25% savings (2-4mph How aero is aero? - BikeRadar ).
Consider you’re on a 200w avg budget for your group ride - that’s about .75mph or so. You’re probably getting a wider rim with that, so you’ll get another 1w or so out of rolling resistance.