Hello jme, The the comfort ratio equation is: D ÷ (.65 x (.7 LWL + .3 LOA) x Beam↑1.33), where displacement is expressed in pounds, and length is expressed in feet.
This equation is designed as an indication of how quickly a boat will react to waves. There are not a lot of 50 footers with a CR as low as 30 and not a lot of 25 footers with a CR as high as 30, although both exist.
If you want, use refine search on Sailboatdata.com to find them. You can also try using the Compare tool on the site to see up to three boats at once. In Compare, use refine search to narrow your results, then Sort by LOA and finally select the boats to compare.
Hope this helps.