Don't forget with digital oscilloscopes sampling rate is just as important as bandwidth. Technically, to see a waveform properly in one go you need a sampling rate 10x higher than the bandwidth. So a 100Mhz scope needs 1GSa/sec, now you can get by with less if the waveform is repetitive, because the scope can interpolate samples to fill in the details, but if you are are trying to trace glitchy behavior you need the higher sample rate.