I dont know the lens.
But I know sigma.

Sigma lenses come in 2 groups: those that are competitive, even with an advantage over the brands.
And the useless ones.
I have some excellent sigma macros and wide angles.
But the sigma zooms i have seen or tried were not good enough.

But with sigma you never know, so I suggest you borrow such a lens and try it.
Look for sharpness and abbreviation in the area 18-22 and 180-250.
Testshoot it and compare with a different brand.

I did that with the 18-200 Sigma, and it fell short.

I believe a lens that is very versatile loses image quality. The lens goes from wide angle to telezoom over a range of 232mm and it also has Macro. Furthermore, f/6.3 almost always requires a tripod. Or you need to shoot at brought daylight, which if often not the time of day you want to be out shooting. Anyhoo, regardless of the brand, I wouldnt purchase a lens like that one.

Here are the lens that will work best for you-

1. 24-70 (Mult-purpose)
2. 18-40
3.  50mm prime
4. 85mm prime
5. 70-200
6. 100mm macro

If most of your photos are taken in small studio go with the 24-70 and 50mm prime

Outdoors with people I love the 70-200 and the 24-70 and the 85mm if you have a good size bag to carry the 3rd lens...

T

i've had a Nikon 18-200 for years and it's GREAT ! i also tried the Tamron and SIgma equivalents and they're not focusing as fast and as good the nikon does, they're also more clunky and they feel cheap.

also the nikon feel plastic and cheap but what do you expect, it's a consumer lens.

if you shoot in F8 it's very good overall, with wider apertures you will see a few problems especially from 150mm to 200mm where it loses sharpness, at 200mm in F5.6 it almost looks out of focus !

the common issue for all these lenses is distortion, but it's not as big as one would expect from such a zoom.

the VR will help a bit but not too much, with the sigma it wasnt easy to shoot at 250mm at F6.3 for instance and as with the nikon it will only come good in F8 or it's gonna be blurry and unsharp.

so, try them out in a camera store and pick the one you like, i would go for Nikon or Canon however.
the Tamron looked the worst of the bunch in my opinion but i've not a Tamron fan.

I got mine a week ago and found that the zoom is a bit sticky if you apply manual zoom while shooting video (I don't)....very sharp zoomed in all the way (unlike the Canon 55-250. Compact and light-weight....happy with mine and on sale for $400 cdn.