Ya, I don't use the double zoom at all. The way it works though is that you can hold right click to zoom like normal and keep it there. It's only when you hold left click that it does the double zoom, so for me I just hold right click and rapid tap the left click when I want to fire to try to get all 3 shots going ASAP.
Part of the problem with Krysae is that it has no ArPn, and even with the mod/ammo, you still can't do damage to guardians from the front. I think all explosive shots (Falcon/Striker/Krysae/Arc Pistol) are like that. It's weird too since in the description it specifically says it has armor pen. So if you shot the Krysae at a Brute's shoulder for instance, it won't do damage, but it should knock off his metal shoulder pad.
Sadly though, I've noticed that my Krysae still does similar, if not better damage against armored targets compared to my Valiant (with armor pen mods). Of course I have Valiant I (mmm Hurricane III) vs Krysae X.
---------- Post added 2012-06-01 at 02:19 AM ----------
Oh ok, another 2 things I thought of.
1) Just like a Brute having those shoulder pads, cannibals and husks get that armor buff from Marauders, so if you noticed Krysae doing no damage to those, it's because the first shot knocks off their armor, and then the second and 3rd shot should kill them. Of course this is inferior to the Valiant with armor pen mods.
2) Krysae ignores shield gate which is one of the biggest reasons it's the strongest sniper riffle. As far as I know, Claymore is the only other gun that ignores shield gate? Maybe Geth Pulse Shotgun. This means with a Salarian, you can energy drain, and kill a phantom in 2 shots.