As a female, I have to make a distinction between "solo" and with a partner.
Solo it is actually a good feeling, not much intense tho. It is just to relieve some pressure, nothing more, mostly because I don't put objects "down there".
With a partner (Sigh, I miss that) it can be slow-building, which leads to a less-intense but of longer duration orgasm.
Or, my all time favourite, when your boyfriend is suddenly competent to please me and, by sheer luck, not only manages to find the right spot inside, but hammers it relentlessy. That kind of orgasm is explosive and make your head float for a while.
To describe the feeling... It is like I-can't-remember-who said: it is the exact moment where the rational thought disappears, leaving the place to pure ecstasy.
I know from my studies that us females have it focused a lot more on the mind and less on the body, so I can't describe you what having a cock would feel. I would be eager to try, but oh well, reality sucks.