I tried designing a monochrome 128x64 OLED into a product about 5 years ago. Luckily a more senior (experienced) businessman in the organisation said "well OK then... but you gotta design it to take an LCD too because this looks kinda risky".
He was absolutely right - the things proved devilishly difficult to manufacture and we only ever saw about 4 samples. One of the big problems is that oxygen has to be kept away from the chemicals that glow, which is rather tricky. For full colour, I was told the different colours aged at different rates (kind of like a CCFL tube which has a brightness half-life of a few thousand hours) so you might have a good colour balance between RGB when new, but after a thousand hours the balance is noticeably off. In our monochrome case, the manufacturers had been a bit too clever and were trying to do too many innovations at once: there were two major OLED technologies and they figured they could leapfrog competitors by using the one which looked cheap in the long run. However, I got a feel for the things.
Firstly, they are usually run by a control chip integrated onto the rear surface (chip-on-glass) which has been cleverly modelled to use the same registers etc as an LCD control chip, although there are one or two relatively minor differences mainly in initialisation, so it was quite easy in the end for the software to control both an OLED and LCD.
The power supplies were a nightmare for our battery-operated instrument, something like 140mA and a +3V / -14V supply sounds about right. We had to make our own for certification reasons, but the controller chips will do the -14V for you IIRC.
Our marketing people were delighted with the look because the customers were generally going to use the device in poorly lit areas, but as development continued we began to notice some disturbing problems.
Firstly the displays would show screen burn after not long at all, just a few tens of hours of usage. Remember how cathode ray tubes used to exhibit this many years ago? So beware if your display will have static text.
Secondly the brightness dropped VERY rapidly within the first couple of weeks' usage.
But the killer was when we tried them in direct sunlight. It turns out that although they seemed really bright in the lab, still (just) legible even when we held them in sunlight streaming through a window, it was a different story when we *took them outside*. Once your eye is surrounded by sunlight on all sides, your pupil contracts and the amount of light you see from the OLED is greatly reduced. Perhaps there's a contrast issue with the surroundings too. Anyhow they were no longer readable, even on a cloudy day.
As I said... this was a few years ago. They may be better these days: survival of the fittest, accumulated improvements over several generations and many millions of units, etc.