It's been suggested elsewhere that the AA-Omniscience benchmark [1] is more representative than the rest. It puts K3.1 about 6 months behind the frontier and the new version of DS 4.1-flash about 12 months. That roughly lines up with my gut feeling as well, at least when it comes to the trickier problems. Still rather impressive, but not quite frontier.
1. https://artificialanalysis.ai/evaluations/omniscience