I've watched these Hass and Knee ascender videos. They are good vids, but they just illustrate a rope walker system. And the rope walker system has been around for over 40 years. The only difference is the parts. Otherwise it's still the same. The wheel re-invented, again. Not to rain on anybodies parade, but that is what it is.
Nonetheless the rope walker is KING.
The wheel has come a long way, a millstone to a wagon wheel, pneumatic tires, lug nuts, solid state rubber tires... All have been advancements of the original simple idea.
You are right about the HAAS and the other guys knee ascender videos, they are just different takes on the original concept of the rope walker. There are counteless ways to utilize both legs in rope ascent system, I have tried pretty much every one I ever heard of and then some (which doesnt qualify anything at all except that I am a rope nerd). The HAAS might not do something NEW, but it dos it in a new way.
In terms of simplicity for the user, ease of setup-storage-on/off the rope, the HAAS is top notch. Its like a sports car compared to a F150, both will get you to the same place, the F150 is easy to fix and cheap, its reliable and it gets the job done... The HAAS or the sports car costs a little more, and is a luxury, but its fast, sleek and purpose built.
It definitely has its limitations... If the bungee wears out you either have to take it apart and replace it or buy a new one (replacing it wouldnt be impossible, I took mine apart tonight and put it back together no problem). The length and adjustability werent
perfect for me, but a few quick customizations solved that no problem.
Overall I think the HAAS is pretty great. It is easy to use, works without issue, it is highly effective, and efficient. The unit is well made with good finish quality.
Without the prior work done on the DLRW, Jerrys efforts to publicize and educate, the internet, forums like this and lots of other factors we wouldnt have any of this stuff. I dont think anyone is representing any of the new setups as earth shattering, never before seen concepts, just elegant innovative approaches to a time proven technique.