The taste of a loganberry is somewhere between raspberry and blackberry, but they are bigger than both. The problem with them (and this may just be the variety I have in the garden) is that the fruit cannot be pulled from the hull until they are past their prime. This seriously limits their use!
The ones in my garden are wild ones - our houses were built on farm land. The only remaining farm land now is the small field where I take the mutt for a quick walk. Unfortunately the blackberries there are usually picked "wholesale" by the same couple every year, although I did get some from there earlier before any of mine were ripe. Just have to remember just to pick any above knee height, for obvious reasons as everyone else seems to walk their dogs there as well
Some Councils are also trying to make it illegal to "pick any part of a plant, shrub or tree" on council property, and when our Council cut the grass more and more of the blackberries disappear. It used at one time to be illegal to spray wild blackberries with any form of chemical or poison, but I think that law has gone by the wayside too.