I agree with tbosco about the sound quality of the pad. I think one thing you have to do is just try the various chord voicings and hear what sounds good.

Another voicing I like is a bass note down in the same register as the bass player would be. And combined with a three note voicing up above and around middle C. Great 3 note voicings can be found in the book 'Jazz Rock Voicings for the Contemporary Keyboard Player' by Dan Haerle. 

You could use a 7, 3 6 voicing or a 3, 7 9 voicing over the root note. eg a CMaj 7 chord could be spelled with either E, B and D over the C root (for a Maj 9th sort of sound) or B, E, A over the C tonic note. (for a Maj 13th sound) One good thing about these voicings is that if the chords move in 4ths or 5ths only one or two notes need to change to reflect the chord progression. You don't want pads moving around too much.

In these cases the pad is going to give you a nice colour. Notice the nice wider spacing between the 3 note voicings. On the other hand a C and G up around middle C might also sound great too. Both right, just different colours. The C and G notes in this case is giving you the foundation or framework notes instead. The Maj 7 sounds needs to come from other parts.