I have long been used. I had a choice between the HF medium range or occasion. I had the chance to recover, and since I can not part with it.
I use them in conjunction with Beyer S 186 U.S. and I eventually dropped many wireless microphones or not I had with "famous" SM58 that I no longer much to the chagrin of some singers ...
Extremely reliable, they have one big advantage: their lightness and grip. Not to mention the sound, the electrostatic cell as we did more.
Many say that HF is the best that has ever been done, much higher than the SKM 5000, which replaced it. I have not had the opportunity to try the 5000, but why not.
However, when I put the same Beyer S 185, the other star of TV shows for years 80/90, front. Indeed, despite its quality, the SKM 4031 is guilty of noise modulation absent on Beyer, who is growing a bit over time, especially with weak batteries. Beyer and his famous head band!
But the quality of receivers, antennas kits etc, is still a micro inevitable that many pros are separated rather quickly, often with regret!
FYI, last used during a concert, 5 SKM 4031 and 5 Beyer S 186 VHF carefree all the great astonishment of the singers in front of these "old" pickups, but soon amazed at the perfs still valid.
However, I dropped the SKM 4031-0 HF (band 8 meters in 37 MHz) too sensitive to interference and long antennae, and the SKM 4031-UHF TV with TNT begins to create their many worries ... snif!