The lighter the wheels- the less rotational weight you have to turn. This can be as simple as putting lighter tyres and tubes onto a wheelset to notice a difference as that lighter weight would be at the extremity of the wheel. But I feel that more more important is the build quality of the wheel. Within a few hundred grammes- wheel weight would not be noticed for the "Average" rider.

But It is those original fitment wheels that I do not like. Bikes are made to a price and one of the Biggest cost savings on a bike would be made on the wheels. Cheap hubs onto a cheap rim with cheap spokes (And it does happen) do not make for a good wheel. Bearings do not run as free as they should- Rims can flex at the wrong time and spokes may not have the right quality to be able to flex ot stay stiff at the correct time. I have always said that the best thing you can do to improve a bike is to fit "Good" wheels but a good wheel builder can work wonders on a stock wheel to make it better.

The original wheels on the OCR were OK- they turned- and were always true. I noticed how poor they were when I fitted some handbuilts to it. Rolling speed on a downhill went up- it turned a few high speed corners into curves and at the end of a long ride I was not quite as fatigued.

I have never had Lightweight wheels- My handbuilts and Ultegras are around 1650 grammes a pair and I have Aksiums that are around 1800 and are good wheels but I don't notice any difference in speed or Climbing ability. But put those stock OCR wheels on and I do notice that the bike doesn't work as good as it should.