Yea sammyfallen. Those are great amps from the early 70s or so. The RMS power is actually 1/2 of the number on the front. So it would be 125 watts RMS. Way loud for guitar and good for bass also. As KramerBassFan said, use it with good and proper cabs and you should be good in either direction. I have the same head that's 150 (75 watts RMS) in power. The reverb vibrato etc. are very cool. I have the matching 2-12 cab with the original Kustom speakers. I also have the earlier 200 bass head and matching cab with 2-15s. Even at 100 watts, it does a great job on the bass.
I met Bud Ross a few years ago at a guitar show in Nashville that featured a huge Kustom display. He is a real nice guy and I enjoyed our conversation very much.
Go here for a shower of Kustom stuff along with a forum - www.vintagekustom.com