I've looked at that one briefly, it looks very useful and versatile. For now I use the simplest "use what I've got" setups I can, so i can afford a proper harness (Onyx is looking pretty good). I have several 2 and 4 foot sewn webbing slings, as well as 2 that are about 2 and 1/2 or so that I made with webbing and a beer knot, I clip a locking carabiner to one side and a large quick link to the other. I got the quicklink for a dollar or 2 at the hardware stand at the farmer's market, I had smaller ones, but the rope had to be passed through it by hand (gate opening was too small) and tying a throw line to the rope would not pass through them. This one is big enough that I can open the gate and put the rope in midline, and the rope end will pass through while attached to the throw line with a few half hitches. After isolating your branch with a throwline, placing the quicklink on the side with the throweight and the carbiner (locked) on the other allows it to be placed using the throwline and weight, the weight comes down, remove weight, attach climbing line, etc.(youtube explains it way better and quicker than I can) A simple overhand knot on the climbing line (make sure it goes into the carabiner side first) will pass through the carabiner, grab the quicklink, and bring everything down (watch your head and make sure the area is clear). If you need a controlled decent, attach the throwline to the end of your climbing line.
I have found that the smallest branches I trust to climb on are too big for the 2 ft slings, so my homemade mid length ones are a minimum.