Prawns are a superb all round bait, I have been using them for years.
They are similar to lobworms in that just about every coarse fish will take them freely. Carn't really think of a species I havn't caught on them. From the carp, tench, bream end, to the predators which just love em, perch, eels and pike.
For most species I use the larger cooked and peeled ones (frozen) from Aldi, these are obviously softer than the raw ones but can be hooked or hair rigged, or cut into smaller pieces for the likes of roach. For targetting the larger perch I sometimes use the tougher/larger raw but peeled ones Iceland sell. When using these larger ones to target perch, if there are a lot of pike in the water you will pick up pike so consider a lightweight trace.