I have used QAD and Hamskeas. Both are good and worked great. Besides the way they operate (cable vs limb driven) the other different not mentioned is the ability to tune the drop timing on the Hamskea limb driven. By attaching the limb cable at a different spot on the limb your launcher will drop and rise at a different times. Roughly the closer the limbe cable is to the end of the limb near the cam the earlier it rises and falls where closer to the limb pocket will rise and drop later. This can be helpful if you wanted to adjust how long the launcher is supporting and stabilizing the arrow. It's not a thing I would choose the hasmkea over the QAD, but just wanted to mention it as it is something that can't be done with a QAD due to the way it operates. For what it's worth I have shot a hamskea for the past 4-5 years and it has been bulletproof for me. I wouldn't hesitate to by another QAD though and it is nice to pre-flip the rest up. Running the hamskea where I hunt (out west) it hasn't stopped my spot and stalk without the ability to flip up the rest.
As far as sights go I have run various 2,3,4, and 5 pin sliders. From MBG-custom 3 and 4 pin horizontal, Spot Hogg- triple stack and the fast eddie xl 2 pin vertical, Ultraview-UV3XL 2 pin vertical, Tru Ball Axcel Landslyde (used it with the UVXL.) I started with MBG then dabbled in the vertical picture with spot hogg and UV, and then went back to MBG horizontal.
The thing you have to watch for with the vertical pin styles is that the vertical pin post may interfere with finding the fiber optic. This is what happened to me. Because the vertical post also surrounds the fiber optic pin end, I had trouble seeing the fiber optic and it blurred the pin for me, especially at the lower pin in low light. It caused me to focus on sight housing and pin and not the target. If there is insufficient light getting to the end of the fiber, the pin color of the fiberoptic gets lost in the black pin housing. The top vertical pin wasn't a problem, it was the pin buried in the post. At certain back grounds that lower vertical pin got lost in the post. I wanted to like the vertical pin style, and ultimately sold both the spot hogg and the UV to go back to a MBG horizontal slider. The pins were brighter for me and easier to locate in low light because each pin had a separate housing and I wasn't trying to a find a fiber and thus my aim point inside a post. So even if the pin was dim you can locate the end of the pin housing and que your eye to find the fiber.
I know this might just be my experience (and also nit picking) and may not be a common thing. I tried two different brands in the vertical style to experiment and had the same problem. For what it's worth I prefer .10 size pins, so that may have been part of it. Out west where I hunted mostly (Oregon) sight lights are illegal so I couldn't just throw a light on to fix the problem.
If you can try both in different situations, back grounds, and low light settings. It wasn't obvious at first but developed after using it in hunting situations. This isn't something you will notice test shooting at the indoor range under brightly lit fluorescent lights.
