Questions about Sigma ART 35mm 1.4 for Concert

I just picked this lens up used for a great price, i read the reviews, it's a BEAST!

I have a Concert this Friday and want to take it out before having ample time to play around with it.

I have a Canon 5D3, I usually shoot most concerts at 1/250th, how much slower can i get this lens and still stay sharp. Pretty active band.

Also has anyone shot a concert with it wide open with good success.

Please share some shots at 1.4 and slower shutter speeds if you have them.

Any advice with this lens you can offer will be greatly appreciated

Depends on what is acceptable to you. I shot a fairly static performer a few weeks ago, and at 1/250 there was still a little motion blur on the head and neck of the guitar. Nothing drastic, but noticeable nonetheless. That was with the 24-70 2.8II. Personally, unless I am in some poorly lit dive bar, I would be very hesitant to use a 1.4 but that's just me.