Also on the other side of the fence. (Professional audio)
But I have a slightly different experience regarding robustness/price of parts.
Beyerdynamic: Super robust (Headsets and microphones), Easily replaced parts for cheap. (of 15 headsets/10 years/daily use, only one needed service, and it was cheap. Own other products too-Mikes- no service needed)
Beyer has a superb reputation in Pro Audio, and it has been that way for 45 years. Their headsets is a studio standard, and their mike-technology is legendary from being a prefered brand with artist ranging from recording Jimi Hendrix' guitar, The Band's vocals and Led Zeppelin's drums in the 60's/70's, up until it being probably the best choice for miking String sections even today.
Speech quality and robustness should not be a problem!
Telex: Own 3 different products, of which two needed service within 5 years. VERY expensive service and parts, new replacement cheaper overall. But Telex, being part of the same company structure as legendary audio names like mike and PA-maker Electro-Voice, Gold standard touring Mixing Console maker Midas and leading concert processing maker Klark-Teknik also has a Superb reputation for great sounding products.
I used some of their aviation products too, and the quality seems familiar. I would recomend either, but you should probably base your decision on your local service and prices.