ThermoWorks just introduced the new Thermapen mk4 for $99. Reponse time remains the same at "3 seconds (reads to within 1°F of final temperature of an ice bath in 3 seconds)"
The prior version is now the "classic" with a "new low price" of $79. At least they didn't scr@w over the folks who bought them on sale or on closeout in recent weeks; 15%-off sale price and the close out prices were $79.
Personally I'm happy with my $25 Lavatools Thermawand. Its spec is "4-5 seconds to within 1°F of final temperature in moving boiling water" and that extra 1-2 seconds doesn't bother me. I'd possibly think differently if I were competing or doing this commercially and had to take a lot of readings all day long.