I'm annoyed because it's lying, not because it's not capable of doing 500MSa/s everywhere.
I want to measure a 50MHz signal,so I setup everything, run a single shot, finally capture that hard-to-catch signal... but then, zooming in shows garbage, 4 pixels dancing, because clearly it wasn't sampled at the advertised speed.
I must know the real sample rate to avoid that! How am I'm going to trust anything if it says 500MSA/s and it's doing 2.5MSa/s?
Show me the real, usable sample rate!
Obviously Hantek wants to sell the big numbers: 1GSa/s!! 8M depth!!
(In very specific and limited conditions which aren't going to tell anyone, you'll discover after buying hehehe...)
So if I knew the only usable memory depth at 1GSa/s was 4K, maybe I would have bought a different dso.
There were other candidates that "only" had 140K, 400K, but if they did so at 1GSa/s, it would have been a completely different story!