I've got a IIa, and I'd strongly recommend that you find a manual and have a good read first. There's a "gotcha" somewhere - I think it's in the film loading and rewinding - that I missed, and it screwed me right up until I found the cause. Mike Butkus's site has a manual, as that's where I found mine.
It's quite complex for the period, as it's combining a lot of functions in a very small package, so it takes a bit of getting used to - no point-and-shoot stuff with it! Needing to have a film in to cock the shutter is a pain as it makes it harder to familiarise yourself with the workings first. However, it's a really top-notch lens for the period, and it's built like a tank. The viewfinder is big - apart from Brilliant finders, the only bigger one I've seen was on a Vito C - and easy to use, though my RF patch is a bit faint.
My verdict - a bit counter-intuitive, but persever and learn the quirks, because the quality is great.
Adrian