They are quite variable in size and some are also a slightly boggly shape I find, but that is how they grow. My seed came from Spain and re what the locals near Barcelona use. The more you pick, the more you get, and I tried to wait until they were at least four inches in length or the flavour was rather too heavy on the green pepper side for my liking. Most of yours look this sort of size Simon.
Rub with oil and grill (or panfry) until slightly charred and it brings out the sweetnes of the flesh, although yes, some can be fiercly hot. They also make a very very good brine pickle with oregano, but I'll warn you, pickling them seems to make them even hotter!
I had so many last year that soe ended up ripening to fully red, and I used these for milder chili flakes
