Back in the days when I was flying the 707 my company SOPs invited not to exceed 15° of pitch nose up for pax comfort.
Maybe so but although I have not flown a 707 it is probable that the body angles at heavy weights may be a lot lower than the 737 at any weights? I am only guessing here.
Even with heavy weights the 737 in general will climb naturally around V2+25 providing the rotation rate is correct and the normal 18 degrees body angle. A slower rotation rate results in fast speed build up and you have to be careful to monitor the flap retraction rate because it is easy to overspeed the leading edge devices during the acceleration phase of clean up.
With a light 737 and faster acceleration the problem of speed increase commensurate with flap retract becomes something you really have to watch - especially if for some reason you only use 15 degrees body angle to acceleration height