I have a Holga 120 CFN - The CFN has a build-in flash, with three color filters to choose from. A tripod socket. 2 F-stops. Bulb setting. Zone focus. 60mm lens - I think mine has a plastic lens.
As wblynch mentions; the film back is held in place by sliders in boths sides, which you mount your camera strap in. (!) You need to cover the back and film counter window with black tape, to prevent light leaks.
I bought it used, some time ago, and I've only shot two rolls with it so far. It's a fun camera, and I've seen people take some amazing shots with it.
I've never tried The Diana, but maybe I'll get one for my collection.
Gandolfi (Emil Schildt) sometimes shoots with a Diana.