am/fm tube tuners

Tuners are the one audio component where it is hard to say that transistors don't beat out tubes. For a start, a circuit called a "phase locked loop" far outperforms other demodulation schemes, and, although it was invented long ago, could not be realized in hardware until integrated circuits became available. Also, analog tuners involve a lot of critically tuned inductors, and the heat of tubes is bad news for them.

I suppose you could make a tuner where the RF stages were transistors and the audio stages were tubes. I doubt that such an animal actually exists.

AM radio is for talk, and ball games. In fifty years I never had AM in my audio system, and never missed it.

The only time that AM radio had anything to do with serious audio was back in the 50s, when WQXR, AM and FM, in NY, broadcast experimental stereo, with one channel on each radio. I set up a couple of little table radios, and was impressed.

The "best" tuner depends very much on your location. If you are in a metro area, sensitivity does not matter, but multipath rejection is important. In all cases, a directional antenna on a rotator does more good than any tuner upgrade. With regard to audio quality, as opposed to the RF performance, this is not so hot for many FM broadcast stations, so is probably not of great concern.

You should try for an in home tryout. This is much more important for a tuner than for other components.