Manual bleed valves can be ok if fitted properly and a small 1mm restrictor used in the pipe before the bleed valve...Hold boost ok and dont spike if set properly...
Best electronic boost controller is the BLITZ Isbc range...Thats what I use on my cars...
Greddy profec B is good too but can randomly loose memory and can die for no reason...
GIZMO is the worst piece to crap in the world...
Apexi AVCR...Good bit of kit when set properly but still only a single solenoid
HKS...I hate them...lol