In response to the "why do you care?" question I think I can make a stab at that -
We all want to be better divers. GUE advertises that they can make us better divers. The top GUE people have excellent diving resumes, and probably know their stuff better than 99% of us. In short, they have the ability to teach us a lot.
We are however told that DIR is a holistic approach and that we have to embrace the whole enchilada or it's for not. Then we get little pieces that sound wrong to us. Now we're torn; we would like to pursue what we hope is better dive education, but we can't really accept some of what we're hearing.
Some of the issues that I would like an explanation of:
1. Does GUE teach that we should do what makes sense to us for our environment, etc, or that we should follow their protocols, configuration, etc. in order to remain standard?
2. On the subject of dive computers - I think we all (or most of us) agree that blindly following a dive computer is not the best answer, especially for tech. Assuming we agree on that, then why such resistance to using a dive computer as a bottom timer, and an extra check to help keep you out of trouble? We generate profiles on V-Planner, write them on our slates, follow them, etc - the computer is just there as one more backup.
3. Why is 80% really such a bad mix? I'm happy deco'ing on oxygen, but there are circumstances when 80% seems like a good choice such as environmental (like a reef that protects me from currents at 30' but would not protect me at 20' - obviously I don't mean Tahoe), and gas supply/management.
The bakers dozen 80/20 article refutes a number of arguments that others have used for 80%, but it doesn't give very many strong reasons not to use it. The arguments that I understand are a) oxygen will give you the best gradient to offgas nitrogen, and b) having oxygen on hand for DCS treatment. The run times in VPM-B for 80% vs. 100% are close to identical for the dives we've been doing (250' TD, 15 minutes), so according to the deco software we're using the offgassing difference in terms of deco obligation is not that great. The DCS treatment issue is certainly valid, and having more oxygen than is available in the DAN O2 kits isn't a bad idea.
OTOH getting fills of 100% at 3000 psi has proven to be a problem. We generally end up filling to around 2200 psi of 100%. If we top with air to make 80% we get almost a third more gas. Why wouldn't we want the extra gas for emergencies? Did I mention that the deco times are within 2% for the dives we're doing (80% vs. 100%)?
Yet the bakes dozen 80/20 article would have us believe that:
"Only a card-carrying stroke would do somethng like this, and showing up with 80/20 is no different than wearing a sign on your back saying "I am a stroke, and have the papers to prove it". It announces to all the world that you have no clue, kind of like wearing clip-on suspenders or having dog dirt on your shoes."
And isn't rule #1 of DIR "Don't dive with strokes"