I have the 6.5-20x44 Viper with the Dead-Hold BDC reticle and it's a great scope. The cross hairs are a little thick though and if I had to do it all over again I would have gotten the V-plex. I thought I would use the hold over hash marks, but I don't. I don't feel they are precise enough. The vertical hash marks are at 1.5 MOA, 4.5 MOA, 7.5 MOA and 11 MOA. 500 yds for my 6.5-284 is at 8.25 MOA. So somewhere between the last hash mark and top of the bottom post. I prefer to click for all my adjustments as I can then dial in exactly what I need. I also have a Nightforce with the NP-R1 reticle that has the hash marks every 1 MOA. I shot it for awhile using the hold over method but found out quickly that I much preferred to click it too. I use the hash marks if I miss on the first shot and need to make a quick follow up shot and don't have time to click. Sorry if this all sounds garbled, it's early and I'm not fully awake yet.
On a last note I want to reiterate that the scope is a great scope. The adjustments are very repeatable and knowing that, I wish I would have just gotten the V-plex.