Probably not a bad choice, I haven't used a Tango4, but I just had a new 4-24 Tango6 arrive, and it's either being returned or sent back to Sig out of the still sealed box. I'd wonder how that got past QC, but with Sig lately, I'm not surprised.
The windage knob is great, but something is off on the elevation knob. I noticed that when I'd make a click adjustment on the elevation knob, it would be sitting nice "in the click" with the number aligned on the index mark (say 5 mils) perfectly, clicks seemed solid etc. However I could not re-lock the elevation knob in any of the click positions. The only way it would go back into lock was to rotate the elevation to a "half click" position. Pull it up, rotate to a click, lines up perfect but won't lock, basically have to push down while turning it till it drops in, which probably can't be good for the gears. I thought perhaps it was just a zero stop, or knob setup issue, so I went through the manual and some videos, adjusted and rechecked everything and it seemed okay, but still had the same issue.
The only thing I noticed that seems out of sorts is that once you remove the marked elevation knob, and pull up on the inner black geared part to be adjusted for clicks, it feels loose like it has play, It's almost like the threaded post that goes through the center of the black geared knob, that you remove to get to the zero stop adjustment is too long, or the black geared part is too "thin".