Pretty good!
Nice job on this. I really like the introduction to this, the strings are pleasing. Thing is, this isn't really special. It's an acapella placed over a simple 4 beat kick, snare, hi-hat, etc. with a melody. Only thing that would make this diverse would be the intro. If you had sliced the lyrics (try using Fruity Slicer if you're using Fruity Loops) and made it a bit more eccentric and exciting then I would've maybe gave you a 5/5! Other than that, It sounds good and I can't really notice the 'errors' you say are in the acapella.
Good job,
4/5, 9/10.
Cheers,
dj JPA