Originally Posted by squirtdad

my experience is less extensive that a lot so the below is IMHO, YMMV

first thing to note good tires clincher or tubular make an amazing difference compared to cheaper tires, but cheap tubulars still seem smoother than cheap clinchers

first tubular the low end Tufo, taped on 36 h GP4 rims. smoother than the Michelin tires i was using (forget which one but they flicked the switch as to how important good (ie not cheap) tires make)

second tubular challenge elite 25mm on 32 h mavic gel 330 rims.... on my 84 team miyata. magical, smooth, compliant made the bike want to go compared to the bontrager clincher 25mm with super heavy tube on MA40 rims. this was at 130psi.
another lesson here, don't discount the impact a light rim/wheel can have on ride

third tubular Vittoria Corsa Control 30 mm on mavic open rims.... super supple nice ride can tell improvment over either corsa g+ or gp5000 in 28 mm would till have them but am in process of a "once in life time build" so sold them

next up but haven't finished wheels or gotten frame yet. 29mm FMP cobble stone, on Ambrosio nemesis rims with hope hubs..... my own hell of the north build (and have set of clinchers also with come rene herse tires so will be able to do some good comparison someday