Personally I have never like the throttle-less controlled engines but of course I don't see wasting fuel to cut short or thin grass. It like all the automatic chokes being tried out now.
Fixed speed walk behind have been around here for at least 20 years here. If you are just now getting them you are that far behind or just lucky that they only showed up lately. As for some these engine the governor springs are very touchy as just not any old spring will work. Nearly burn one engine by using the wrong spring.
