The 456 might feel a bit slack & heavy after the dale. The Soul is a lovely frame, but quite expensive.
It's worth having a look at these two as well:
Pipedream Sirius & Scion or Dialled Bikes Prince Albert
Both more nimble in terms of their geometry and with nicer tubing than the 456 and cheaper than the Soul.
Not to be a chuffnubbin or anything, but the Dialled PA is 'Reynolds 725' steel.
The On One 456 is 'DN6' Steel (named after On-One's postcode)
No matter what the name is, both of these are exactly the same, 4130 (this is the industry standard AISI designation) double butted steel.
Interestingly (ok, not very) scroll down to the bottom of the Reynolds info and they have a stiffness chart, all of the steels are shown to be stiffer than the 6061 (ok, so there's 7005 as well but I didn't notice any info on that) which is the regular Alu used in bike frames. And Aluminium frames get slated for being 'stiff' and steel is supposed to be 'compliant'.
It's all a load of old trousers, but @Chak I found my On-One seemed to feel larger than it's 16" frame size should have.