In reply to glaramara: Depends how much snow there is. I soloed it in November in the afternoon with a pole, but no axe (not particularly advised). The rock was dry though, and there was a fair bit of grade 2-3 with significant exposure. Possibly a short less exposed crux of vdiff. Apparently there's a few ab stations off single cone, and there's a snow gully between the two, not sure how it is in summer though. It's only another 15 mins on rock to the summit of single cone, I remember the descent to the col from double cone taking longer.
So in summary, take moving together gear plus axe and crampons in winter/spring/early summer.
Great route. PD+? Guides say up to 8 hours, but has been done in about 1 and a half. I took a middling 4 and a half.