G, A, C, D, E, G still sounds very major, although would be great over a Gmaj13 or Gmaj6 chord. It has the same notes as a C major pentatonic scale.

It does not have the F, which is what gived the mixolydian mode it's "dominant" or bluesy characteristic.

If I were going to use a mixolydian "pentatonic" scale, I would use G, A, B, D, F, G. This has the 3rd and 7th notes of the G7(dom) chord.

Play both of them over a G7 and you'll hear what I mean.

My opinion.

Peace,
-Rick