Also, most of what I've read seems to have some conflicting reports, even within the same user and same report; that is the lasting stimulation, but relatively little desire to do anything (at least physically) with that energy... could someone elaborate? The dosage also seems to vary rather wildly... is the large "attack" dose and booster dosing (as recommended on erowid) later actually a good strategy, or will this just lead to using too much product and unpleasant vasoconstrictive effects?
I'm probably going to try this soon and after the low dose safety tests, i'm guessing the therapeutic range to be ~100-160mg? How nasty is insufflation?
When I first tried methylone, it had been a very long time since my previous brief occasional experiences with entactogens in the form of MDMA. I also had no history of stimulant use (er... aside from a caffeine and nicotine habit). I found c. 150 mg oral to produce a mild but pleasant effect, and somewhere between 180 and 220 mg oral to provide more full-on effects. Towards the top of that range there was more likelihood of persistent stimulation after the brief (c. 30 minutes) more entactogenic phase. At that time, I considered the persistent stimulation an annoyance, and I would have assured anyone that there was no point taking any methylone after the initial dose, because I found it would just extend the stimulation without rekindling the loveliness of the entactogenic phase.
In recent times, using both methylone and mephedrone, I have come to enjoy the stimulation that both of these substances produce. I'm not at all sure that is a good thing to have learnt to enjoy. My new pattern of usage (learnt with mephedrone; transferring somewhat to methylone, now that I've sworn to avoid mephedrone due to its worrying effects on heart on the following day) is more like a 250 mg oral attack dose, followed by insufflation at a rate of between 50 and 100 mg an hour.
I guess it depends what you're after. If you're interested in entactogenesis, I'd suggest taking an oral dose of between 160 and 220 mg and not touching any more for a couple of weeks. I guess that sort of dose, at the lower end, offers pretty much just the entactogenic phase, but at the higher end might leave residual and uninteresting stimulation after itself. If you're more interested in the stimulation itself, you could take the other (presumably rather less healthy) route of taking a higher initial oral dose and boosting with insufflation (or just repeated oral administrations) to keep the stimulation at an enjoyable level.
ETA: Re: how 'nasty' insufflation of methylone is... it's fine, in my experience. The drip's not too nasty tasting, nor does it make my nose or throat feel sore. Well, a little pain, maybe.

But not sore and inflamed, like my current batch of 2C-C does.

(A previous batch of 2C-C was absolutely fine...)