From lomography site :

Using Agfa’s mysterious “eye-vision technology” this increasingly rare color-negative film offers outstanding color depth and absolutely wonderful red tones – to the point of imparting a totally unique warm-saturated cast to most daylight images.

A roll of Agfa Optima II will give you warm colours with slight contrast which Agfa films are known for. And undeniable sharpness on your photographs can be seen because of the optimum colour couplers it has which intensifies its saturation and improves light sensitivity. Also, can handle enlargements as much as you wish without worrying any deterioration in your shot’s resolution. With all these combined, all you have to do is to admire and feel the intensity of your photographs to the optimum level!

From flickr :

OPTIMA is the professional film that's perfect for every role. With its incredible range, sharpness and color saturation, OPTIMA always gives an award-winning performance - even in the most challenging roles. Because Super Inter-Image Effects (Super IIE) and optimum color couplers intensify colors where life casts its shadows. And the innovative SEM (Surface Enhanced Multistructured) crystals transform light with 30% more efficiency into energy for your photos. So you get finer grain, thinner film layers and, of course, outstanding sharpness - even with high enlargements. All that with a stability and reliability that makes OPTIMA a modern-day hero in everyday and special applications. So there's always a happy end.

There is a Agfa Optima Group at flickr serves 260 pictures:

And for your question about exposure change , it can be everything. You must try one roll and see. If the colors shifted too much , you can scan as bw.