"The 465B is also a very good scope and, though it is a 100Mhz unit, they typically are good to 150Mhz or so."
That's a bit of a misleading statement. The specified bandwidth of the 465, 465M or 465B is 100MHz. Being "typically good to 150MHz or so" does not mean that they will be amplitude-accurate. Most 465s will have their 3dB bandwidth point over 100MHz, but not as high as 150MHz .... maybe more like 105 or 110MHz. Any higher, and the amplitude measurement will not be correct at all. Even at 100MHz, a barely-in-spec instrument will have an amplitude error of -3dB. A 465 is "good" to a lot higher than 150MHz. It will still trigger at those higher frequencies, still display the waveforms (fast-rise pulses will not appear as fast as they really are and amplitudes will be lower than they actually are) and you will still be able to use them to measure frequencies, although the 5nS/sec you can get at the 0.05µS TIME/DIV setting with the 10X horizontal magnifier on may not be fast enough to separate individual cycles for easy measurement.
Dean