Most oxygen generators do not provide adequate volumes of oxygen at altitude due to lower atmospheric density at the heights we fly. I am only aware of one that is capable of providing sufficient supplemental oxygen above 10,000 ft. MSL (And, no, I will not name the particular brand, as it is most definitely not approved for aviation use.) Pressurized oxygen delivery systems are well known and researched over the last 80 years. They are simple and reliable and do not require excessive amounts of energy to operate. An electrical failure with a generator could leave you in a potentially dangerous situation, high altitude with an insufficient supply of "brain fuel."
I fly with oxygen every time I take off. (My field elevation is 6,200 ft. MSL) A few years ago, I analyzed a season's worth of flights, and discovered that, out of 142 hours of airtime, I was above 12,000 ft MSL for 126 hours. A thoroughly tested oxygen system is an absolute necessity to keep me safe. And it also keeps me from singing stupid advertising jingles from cereal ads on the radio. (Yes, this happened during my hang-gliding days before decent O2 systems were available.) I've been selling and installing oxygen systems since 1991 for hang gliders and sailplanes. The Mountain High EDS system is simply the best solution available, and I continually research any "new" oxygen delivery system that hits the market.
Note: This is from the Aithre website referenced above.
"However, if you plan on using the Turbo for oxygen above 12.5k MSL, it is advisable to consider a small backup oxygen bottle."
Is that clear enough?