I recently was blessed to be able to try DOC (at a dose of ~3.25mg). I found it phenomenal--it has a lot of the sparkle and 'bells and whistles' of a decent dose of an ergoloid like LSD, with fantastic visuals. The only thing missing was the emotional/empathogenic effects of LSD; this one was all cognitive (and in sub-psychedelic doses might be a great nootropic). It does produce more physical/PNS stimulation than L, but (strangely) not as much as 2C-E. Unlike DOI, (which is also wonderful, but too long-acting to be particularly practical), the duration of DOC is more managable, more akin to ~16 hours than the 28 merciless hours of DOI--after a DOI experience, one feels completely 100% spent for at least 24-48 hours afterwards. I can't say I have any interest in DOB, as it is purportedly far less friendly on the body than DOI, but just as long-lived.
Thus far, DOC is my favorite psychedelic amphetamine, but I would be interested in trying DOF at a dose of around 15mg--my bet is that it would possess a shorter duration than all the rest.