Your legs were probably shot. It takes awhile to be able to do a grueling hike and then turn around and ride right back down it. Good news is that you'll get there fairly quick if you keep splitting.
Do yourself a favor and get some Spark bindings or go full on with a Karakorum kit. Although Spark is introducing a new interface for next season that looks absolutely amazing. The difference in performance is huge with splitboard bindings, I don't know if that is truly your problem but it will make your life easier. Skinning, weight, power transfer are all better with splitboard bindings.
K Clips are pretty decent. I am using them on my SL Split and they are pretty great. The thing is torsional wise, Voile Chinese hooks are better. So there is give and take. I guess I am not going back to Voile Chinese hooks on my main ride, so that speaks volumes as to how I like K Clips.