I'm about as light as I want to get : 80kg and 187cm tall.
Currently I'm on 1,400 miles for the year and 80,000ft climbing
I have a hybrid too which is pretty heavy which I use for chasing my 5 year old around the park. I did on a couple of rides on it recently and it was still pretty fast : https://www.strava.com/activities/895507682
I'm a similar high/weight.
Nice 19Mph Average speed, I'm only averaging just 10-11 Mph, but that's mainly due to using cycle paths (on pavements) so lot of having to slow/stop at crossings, dodge the myriad of school children that block the path. I can hit 30 Mph in one downhill section, but there's nowhere I can really let rip for a sustained time. :<
I not mad enough to risk using the roads in those sections at the height of rush hour.
The light bike must be nice on a steep ascent.