Depends how long since I masturbated last, and how interested I am in a new "find".

Roughly 10-15 minutes most times though could be 30 minutes if I'm not terribly inspired but still want to release.

I tend to read through lots of posts, watch porn, chat about sex, cam wank if I can, playing with my cock and balls for hours while doing all this then finally cum just before going to bed. Love to keep the feeling for as long as possible

It depends on my mood and what I feel for. My cum record is 54 seconds to ejaculation, furiously stroking my cock. Was a poor orgasm.
My best orgasm comes when my stroking lasts between 30 to 50 min, gradually building up the orgasmic energy. My brain is still with me and I shoot a lot and orgasm becomes intense.
I tried longer sessions but I tend to become bored and dont focus on the pleasure.
Something in between is the thing for me...

Keep

I usually can get off in 5 minutes watching porn.