On our recent trip we used SVG Air after having used Liat (uneventfully) on previous trips. This was for reasons of scheduling convenience at higher cost. In our opinion it was well worth it and we would do it again with SVG.
Be aware that the plane will make a few stops in each direction which was not obvious to me from the web site/schedule. On the way to St. Vincent from BGI we stopped in Union and Canouan. On our return to BGI, we stopped in Bequia. In all cases this was for 5-10 minutes maximum. It was really interesting to see the islands from the air. We will take SVG on our next rip for sure.
One thing to be aware of is that when you get to St. Vincent, you might have to find an Immigration Officer as they did not clear us in on either previous stop and the people in St. Vincent thought they had. We could have easily bypassed immigration but thought it prudent not to.
Bob