with all this rain we are having i would stick to having two myself might come in handy, must admit ive had the single wiper conversion on a few cars and have quite liked it but i think it looks better on some cars but not others, had it on my fiesta rs turbo and my series 1 rs turbo both looked good and think it would suit the golf seems to look better on hatchbacks and saves on buying 2 wipers.
I had a single wiper on the Escort, was a complete PITA. Would never sit dead centre and was a distraction when driving, also I had to adjust it to sit on the bottom of the screen on every MOT.... It took twice as long to clear the windscreen in the rain so I always had it on full speed