
6m is an odd band in that there is not a lot of local SSB traffic (I think) and when the band does open up for either Es or F2 propagation the polarisation probably doesn't matter. Certainly I am able to work (at least) as much DX with the vertical on 6m as I used to work with a rotatable horizontal dipole. The antenna works very well for local (and DX) QSOs on 6m, 2m and 70cms FM of course.
OK, if you want to work marginal propagation modes (e.g. MS using JT6m) or tropo DX then a beam would help. But, if you are prepared to go DX hunting when the band is open, then I think a simple vertical is all you need.