i can honestly say that i learned using headphones and thought i was getting a better sound than i was. going backnow and listening to all of the stuff made in headphones, some of it is better than i expected on a great set of monitors, but for the most part...

...not so hot.

do yer sequencing in headphones, but if you don't have proper monitors for mixdown...go to someone's house who does. you will be happy you did.