nightmare
I don't know about Cakewalk, but when I was using Cubase (ie, before I had any sense), I once tried to import a big orchestral piece from Cubase to Sibelius as a bunch of MIDI files, to create the score for the orchestra to play from. It was SO shoddy - every time there was a tremelo or something it confused the hell out of Sibelius and got imported as gobbledigook, and screwed up the timing for the rest of the movement.
I swear it would have been quicker to just re-play the whole thing into Sibelius - its a very easy and intuitive program to use, in and of itself.
Might be OK if you're talking purely about simple pop songs in C Major and 4/4. But get to far beyond that and you might as well forget it.