I love this crowd. It is by far the most opinionated, but educated online firearms forum that I participate in. Tough audience. There are certain religious affiliations that simmer beneath the surface. One common theme is the bias against Leupold. I get it. They have been behind the curve in innovation for some time now. I actually have a lot of respect for Leupold, but also agree with the lack of innovation. This spills over into brands like Sig.
I have said before, I am a scope slut. I love and leave 'em the next month, so I have used many and broken many hearts. I am an equal opportunity lover.
Here is my take: First, Vortex is a fucked-up brand. In fact, there is no Vortex brand. It is an amalgamation of every level of quality and every price point imaginable. I have no clue how the maker of the Sparc and the Strike Eagle can also make the PST Gen2 and Razor scopes, let alone the scopes in-between. The Razor HD and AMG are great scopes, inspite of, and not because of, the Vortex brand name. The Razor is not only a great optic, but also if solid and robust in external construction.
The Sig Tango, I have found to be a decent scope. The Tango4 is made in the Philippines, and I found it to be a good value and decent glass. In the Vortex line, I would compare it to the PST Gen1. I had some troubles with the Tango4, in terms of movement of the zoom lens. The Tango6 was a mark better, and I found it to be a very good optic, and has some neat features, like the internal cant indicator. The turrets are not as solid as the Razor, from a standpoint of throwing the scope down the driveway or hitting in the woods. If you are at the range, I have found the Tango6 to be very good. Is it as good as the Razor? Pretty close. In my opinion (just that), I would put it more on a par with the PST Gen2 -- maybe a little better -- but not as all around good as the Razor HD or AMG.
I think both scopes are an upgrade from your Bushnell.
Just some observations and opinions based upon what brands you asked about. I might be inclined to add a quick look at Steiner T5Xi or NightForce.