Do any still use an older high end tuner from the past?....

stereo5

FM HD radio is sounding very good.

Really?
An FM station using just one HD sub-channel has a maximum of 96 kbps. It’s worse if it uses multiple HD sub-channels. So HD radio is kinda like mp3 files; good s/n, but that’s about it. In other words, it’s anything but "high definition," as iBiquity/Xpiri acknowledge.

I have a Sansui TU-X1.

You need his wingman AU-X1 now.

I occasionally use a Pioneer TX 9500 with Bic FM 10 as an antenna; unfortunately the commercial radio stations in my area infest the ether with bad music and transmissions that saturate the signal.

There are lots of used tuners on the market, but in my opinion most are not worth over $100. Clearly there are exceptions.My experience is that the old Philips AH673 is a good tuner, once it has been refurbished and aligned. But the cost of a good refurb is several hundred dollars. A Magnum Dynalab MD90 tube is close, but it depends on what each tuner sells for. Check out my comments on Canuck Audio Mart tuner forum.

I use an MR71 I have owned for over 20 years. Sounds great.