I have had 840 in hand just not spent time with them like I should have. so, I have a new 527 on the board now and trade options for the 840 2x or 3x to give it a true go.
I also run the element Theos, and love it
ZCO 527 @X reticle.
Great glass, dependable, repeatability, I'm able to see all of my miss's and hits with the 5-27 power range. Great CS "IF" ever needed. the 2X has great aiming point for hold overs.