Are 45's really THAT good?

What really matters is the speed with which the vinyl passes the stylus, and this varies quite a lot from the outside to inside grooves. 33 rpm is perfectly good for the outside grooves, but there is often significant degradation when the inside grooves are played. With a 45rpm recording the inside grooves will not exhibit this degradation. Of course, the 45rpm speed was invented for pop singles with small diameter, and the speed was appropriate for them.

I have heard back-to-back playback of ancient recordings (c 1910) raw (as recorded), and after digital restoration. The raw sound was very noisy and lacked any high or low frequency signal. However, it has been discovered in the course of analysis of the digitized signal (unexpectedly) that highs and lows do exist in the groove, but at a level so attenuated, and so overlaid with noise, that it requires a computer program to extract the information. However, when the noise is removed by various ingenious methods, and appropriate equalization used, the almost unlistenable 1910 recording sounds about like an early vintage 33 rpm recording.

Herman...I have a boxed LP set of Benny Goodman recordings from 1937 Broadcasts. The masters for these recordings are "off-the-air" (AM radio) check recordings, made, no doubt, direct to disc. The AM transmission was likely the limiting factor on audio quality.

I treasure these LPs, but I recently bought the same recordings on CDs. I don't know how the recordings were remastered, but the results are excellent. There is very effective software available to remaster old recordings, and I don't know why anyone who was transfering to CDs would fail to use it.