True Temper OX Platinum is comparable to Reynolds 853. Reynolds 631 is actually the same tubes as 853 only it's not heat treated for strength like 853 is, only air hardened (which sounds to me like they weld it and let it cool!). So the welds are quite strong since they get hot, but the overall tubing is less stiff than 853. I had a Jamis Quest and have a Jamis Coda, both 631, and they are very comfortable bikes. I'm a lightweight 145, so I can't comment on the stiffness as I never felt any lack of rigidity.
Depends on your idea of better.