I think they just sound a bit naff lol when your used to hearing a screaming Fox alarm. No idea on Delk reliability - not had them long enough, feel a bit flimsy if you know what I mean but no probs yet.
Me and my mate were on the mill with new Delks, he gets a take and doesn't recognise the sound so we are saying, go on then someone hit it!!!
By the time he realised it was him, ran to his rods and lifted into the fish it fell off - unlucky for your first take from a venue - we'd only been there a couple of hours lol
I did the same in France, didn't recognise the sound as being anything to do with me.