Engines not designed for 'real power' are unsuitable for any use.
Maybe this seems a tad presumptuous, but I made a comparison earlier in another thread that no one has commented on yet, and which I thought was rather apt to the general discussion around here.
"This just in: Modern airliners are horrible designs. All of them. NONE of them have the ceramic heat tiles on the bottom of the fuselage and wings. How are Delta Airlines' fleet of 737s ever going to enter the earth's atmosphere at orbit speed without those tiles? Must be those nagging bean counters at Boeing. Always trying to make a buck and rip off the customer. Lives are at stake here guys! It's that important! "