I guess the 6-4 chord in common practice music is typically seen as a "cadential" 6-4, used to embellish the chords around it by means of bass arpeggiation.
In rock music, however, a I chord in second inversion could be part of a descending bass-line progression.
The issue is that (in the key of C major for example) a C major chord with a G in the bass sounds unstable--not the best start to a verse progression (ex. I64-IV-iii-V64).
Is there a way to lead into the I64 chord or voice it a certain way so that it is more stable/rich? Or is this chord typically avoided because of it's inherent instability and I should look at a progression such as I-I42-vi-I64 instead?