Nice, with the subtle wah-wah (hard to imagine that adjective being used with this kind of guitar playing style; listening to it again, though I'm not sure if it is in fact a guitar, anyway), the Kendrick version is the smoothest certainly with the vocal-line held level with the music. I really like that over-dramatic build-up that fades, coming back every now and again.
In contrast, the Gwen McCrae version released the following year with its near identical, if not identical backing-track, has a much stronger personality that drives it along it along, making it a more assertive statement that comes through with the refrain ‘What can I do?’
Check out this interview with McCrae by a Swedish woman who goes by the name of Miss Funkyflyy, it's full of strong background information on the much-sampled, respected Soul star from the 70s. I particularly liked the interviewer's personal tale of discovery, where the enthusiasm comes through:
Madlib (apparently) sampled McCrae's version of '90 % ...' on his 2001 Beat Conducta, Vol. 0 Earth Sounds release out on Stone’s Throw records, 'Tape Hiss (Dirty)' (and sampled another McCrae song, ‘I found love’ on his 2008 ‘Gamble on ya boy’)