Reports on cardiac effects are mixed. It helps, as with all stims, that you are generally healthy. I've not personally experienced any cardiac effects other than a slightly increased blood pressure and i generally take doses of 200 mg and under.
Rio read below
.. yes.. it can make people a bit more libidinous

For me it won't make me attracted to someone i'm not already attracted to, but if i like somebody and they like me?... let's just say that there aren't any performance issues until acute dehydration sets in. Maybe about 10 hours in i'd say for me, but your mileage may vary. Some people report a lack of arousal or an inability to get things moving. I wonder if simple dehydration might be having a greater effect on some users than has been mentioned? It does seem to have pronounced diuretic effects for everyone i know who uses it.
Along with a few others i've found it quite useful for communication work as well. Very much like MDMA for me on lower doses. I might start the night off with 125-150 mg oral ingestion and then insufflation of 30-40 mg. Afterwards i just do bumps up to a session max of around 500mg now. Has been of great use working on some very deep seated personal and interpersonal issues. Although in sensitive individuals you might want to schedule some away time for a few days after the come down.
Yes it can be quite difficult to put down sometimes, so be prepared. I might even suggest laying out the amount before hand and putting the rest with a trusted friend or something.

I have had some binges, but i
learned from them. One of those lessons is to treat this with respect and put it down when it's lost that magic. You'll know what i mean...
Stay safe and have fun and learn something! :D