When I was upgrading my bike focusing on lightness (my '73 with a 3.2 is 2174 lb, so I'm a bit of a lightness freak), I found these wheels that seemed to get decent reviews on forums:

Yoeleo Tubular Wheels

I shaved 4 lbs off my older carbon fiber bike to get it down to 18 and have been thrilled with it ever since. Cranks, pedals, handlebar & stem, seat post and seat.

30 years of riding on and off (way more off than on), I had sew-ups and always loved the feel over friend's clinchers. This bike I have has fairly old Mavic Ksyrium wheels with new Continential Grandsport Race tires. Even with a ton of miles on them, I just can't get used to the feel (or lack thereof) and am considering the Yoeleos again, or a set of aluminum tubulars.

On carbon fiber vs. metal, CF is unidirectionally strong and relies on weaves to achieve equivalent 3D strength to omni-directionally strong metals like steel, aluminum, titanium, etc. Mr. Ahab can certainly speak authoritatively on the subject, I only worked for an early 90s pultrusion company making CF parts for the Stealth Bomber, hockey sticks for Bauer, etc. and picked up a few things along the way.

I can only find 17mm inner width on the Zipp website. Where have you seen 21mm?

I haven’t seen 21mm inner width on any rim brake wheels except the Bontrager wheels so I’d sure like to hear about any others.

Dad has Zipp 808 on his try bike. Wicked.

No, the a33's and the equivalent Boyd's (altamonts ?) are 33 mm deep by 21 mm wide. Not carbon, but perform like the zipps in testing.

Try the new tubeless clinchers. The feel of good sew-ups with the ease and lower cost of clinchers.

Thanks Mark, I'll do some research too. I never got flats with my sew-ups. Roads around here are terrible in terms of pot holes but little debris to puncture tires.

The new road tubeless are so good that the pros are switching over by choice. 25-28mm vs the old 21-23 is the new norm. Lower pressure gives a smooth, high performance ride with lower rolling resistance. If a tire is cut, a tube can still be installed but it's still less hassle than a sew-up on the road.

I'm a fan of tubeless road tires and I've been running them for about 5 years, but I understand the pro's have had less than desirable results with tubeless and almost all if not all have gone back to sew-ups except for time trials when the lower rolling resistance matters.

I ran sew-ups for many years when I worked at a bike shop since the wholesale cost was easier to handle and I never thought changing on the road was too bad. I never bothered to glue them on out on the road, I just took it slow in the corners so I wouldn't roll one.

I've been thinking about going back to sew-ups since I can afford them a little more.