Sorry, I never stated why I hate them...

1) too easy to adjust. These are rarely properly set and sealed so cannot be adjusted.

2) Most are cable tied to a boost hose or left dangling in the engine bay .... utter bodge IMO.

3) Unstable boost levels depending on ambient air temperature due to the thermal expansion of brass.
(plastic AMAL valves are less suseptable

4) I just really hate them !! lol