Comfy and better wearing than Vittorias. Use them on Envie 6.7s my only gripe is that the cotton taping doesn't extend as high as Vittoria which makes mounting the front difficult to center as the 26mm width of the rim hides the ochre color of the glue covered cotton casing.
I have ridden these arenberg/roubaix tubulars for about 4 years now. I get around 6-7k miles from the fronts and 3-4 on the back tires, and have only had one flat in 5 years and many miles. They ride very smoothly, and mount easily. They grip and last better than the similar vittoria tires I've bought, and the 25mm carcass means I can air them up to 85-90 and have a smooth ride.
Doesn't get any better unless you pay for FMB etc. .
After years of using tubulars, I'd been on Veloflex clinchers for a couple years. They seemed almost as good. Then I went back to these Arenbergs. I'd forgotten how nice the ride is on tubulars. The rough, crappy roads that were terrible on clinchers (even at low pressures) were OK again on these tubulars. They reminded me of the great ride provided by Clement Criterium Setas back in the 70s.