Not a real graceful looking aircraft. I guess for the time 1K hp engines was top of the line. The 299 (B-17) which competed in the trials had a four 750hp engines. This was a substantial improvement in overall horsepower and it showed in higher top speed and higher cruising speed. There's something to be said about aerodynamics here also. The B-18's successor resolved a lot of those aerodynamics in the DC-3 (C-47) which is one of the greatest stories in aviation.