I have about 8 hunts in a saddle and I've developed a few thoughts about how it works for me.
First, I find it easier to sit still in a stand than in a saddle but that may just be me. Connection to the tree is alot more dynamic in a saddle. I think I'm also more comfortable in a stand but that seems different for each person.
Second, I'm not saving as much weight as I thought I would over a light stand since you still need sticks, ropes, etc. I found the saddle system easier to pack and quieter to carry than a stand though.
Third, I think alot of folks would find climbing with anything other than sticks or a similar approach would be quite a show and a real sweat-fest. They make it look quick and easy in videos to climb with one stick or even no sticks but I bet that isn't generally the case.
Fourth, unless you just like to tinker, I'd just buy a saddle and avoid the DIY approach. If you value your time I'm not sure you will really save very much and you won't have much resale value if you decide it isn't for you.
Finally, even if I didn't ever saddle hunt again I think the saddle is a great fall restraint. I think I feel more comfortable in the saddle than any vest or harness I've used.