Only had a quick scan of comments about aquadapter turning on but not turning off properly.
This happens with me, with hot and cold using mk2 adapter. All you have to do is give the hose a little push so it releases pressure on the turning mechanism, I do this either just after turning on so its ready or just before turning off. I do not think its a real problem, It does not slow me down at all. I use my 8mm hose as pole hose so the weight of that pulling on the spring probably does not help, But like i say its not an issue for me, I love the aqua-dapter.