The Conshelf 14 is still made and is used by the Navy SEALs as well as a number of other military branches. Some of us who have been diving for 25 years or more have 6-10 different regulators to pick from. We rid ourselves of the stuff we don't use and implement our "good old favorites". As for a pony I would pick a regulator whose design is as simple as possible with a proven track record. I really can’t think of any regulator with a better record for this application.
Just because a regulator is old doesn’t mean it’s obsolete. This is not the computer industry…Technology has not changed much in this field in the past thirty years. As long as you have it annually serviced the regulator should perform as well as it did 20 years ago. And as for quality how many regs do you own that are 20 years or older? My Conshelf is from the early 80's…if that’s not quality I don’t know what is…
http://www.aqualung.com/products/conshelf_xiv.html