You're right about the smaller slow down between strokes, I didn't think about it.
Anecdotally, I have a gravel bike with two different sets of wheels, 28 mm and 42 mm. I use the 28 mm for asphalt only rides, especially uphills, and the 42 mm for mixed terrain flat rides. The 28 mm feels immediately faster, it's like 3 or 4 km/h for free. On the same training circuit the average speed is higher. The only differences between the two sets are: 1) the weight of the tire and the inner tube because the rim and the rotors of the brakes are the same and 2) the 28 mm tire is smoother but the 42 mm is relatively smooth too.
BTW, I know that should use a wider rim for the 42 mm but the previous one broke right before one of the announced covid lockdowns and I got what I could find. We could cycle alone during the last lockdown and I didn't want to go asphalt only for a couple of months or so. I'll buy a wider rim next time.
So, I believe that the only difference between the wheels is the tires, but I'd say that there's probably more difference than the weight, and that would be rolling resistance.
I've got 3 bikes I ride -- a tandem w. 26"xwide supple road tires, a 12kg gravel bike running supple 650x48 (now, but have done 650x42 and 700x35, and the stock tires), and a 8kg carbon road bike running fair 700cx25.
I'm sold on big tires, because narrow/high pressure is too tiring.
Some anecdotal evidence:
The gravel bike shipped with the most horrible tires I've ever used, 38mm, 800g (each), felt like riding through deep sand. I used them for maybe 10 miles total till the good tires were delivered. It wasn't the weight, it was the super stiff sidewalls that just _sucked_ the energy out. I haven't noticed a major difference between the other three different tire sizes I've run on it, but they've all been running the same casing, Rene Herse ExtraLights (but the point of the light is that it's a super supple casing, so low rolling resistance. The 650x48mms are about a 400g tire).
Last summer, the gravel bike was out of commission for a week, so I did my hill workout (6x5 minute reps, + there and back) on it. Went back to the gravel bike the next week. ET difference between the two rides -- 10 seconds over 1.5 hours. Much less than the usual week to week variation on the same bike.
The tandem used to be on Schwable city 40mm tires, which are tough and durable. Went to RH 44mm in front and 53 in back, and average speeds over the next 6 rides went up by 1.5 mph (from ~16 to 17.5).
In short, I don't think weight is a predictor, but tire quality and rolling resistance is. High pressure leads to suspension losses as your body bounces and absorbs energy, stiff tires lead to hysterisis losses when rolling, low pressure, supple is both comfortable and low resistance.
Anecdotally, I have a gravel bike with two different sets of wheels, 28 mm and 42 mm. I use the 28 mm for asphalt only rides, especially uphills, and the 42 mm for mixed terrain flat rides. The 28 mm feels immediately faster, it's like 3 or 4 km/h for free. On the same training circuit the average speed is higher. The only differences between the two sets are: 1) the weight of the tire and the inner tube because the rim and the rotors of the brakes are the same and 2) the 28 mm tire is smoother but the 42 mm is relatively smooth too.
BTW, I know that should use a wider rim for the 42 mm but the previous one broke right before one of the announced covid lockdowns and I got what I could find. We could cycle alone during the last lockdown and I didn't want to go asphalt only for a couple of months or so. I'll buy a wider rim next time.