I took it until my nose was so damaged that I needed a to take a break. I spent a fortune on nose sprays and nose balm. The weird thing was: I took it several times a day, although I didn't experience positive effects from it anymore.
Apart from that, it really is a nice chem, it makes you chatty and at lower doses I found it relaxing. Also, it makes the days go by faster, I would spend hours organizing my mp3 collection and not get bored.
There are tabs available now, I highly recommend sticking to these, because my nose never really recovered and it's already a month since I stopped taking it.