I had a zapp for my son about a year ago, and got it for very similar reasons to yours, not taking up much space and wanting something light and compact for a holiday. I loved it at first and it was great to push etc, but when it came to taking it on a plane, it all started to go wrong. Firstly I was under the impression I would be able to take it on as hand luggage as it folded so small, but no, had to go in with luggage. Obviously this meant having to chase around the airport after my son while waiting for luggage at the other end, then when he got tired I had to carry him. He was 2 years old then so not easy to carry!! Also when the pushchair came through, we noticed that the covers off the brake plates had been damaged, and also the frame was scratched quite badly. I knew the staff wouldnt exactly handle it with care, do they ever, but I considered this to be a little inferior manufacture-wise with the cheap plastic covers on the brake plates. We then had to spend the entire holiday struggling to put the brakes on, as there was only a little piece of plastic left to apply your foot to, no bigger than a 2-pence piece.
Once on the holiday itself, we also found it not very practical. There is no shopping basket underneath so couldnt even carry a bottle of water without taking a bag. Couldnt hang bags off the buggy as it is totally unstable with ANY extra weight on the back. We also found the seat position a bit of a problem as we couldnt recline it. At this point my son wasnt having naps in the afternoon as a rule, but on holiday where you are out and about all day and generally doing stuff all the time, it was a huge inconvenience when he did fall asleep as his head would flop forward, or otherwise he would slip sideways and either way would wake up with a stiff neck. Not so much of a problem during the day as he was quite happy to walk most places, but come late evening after eating out or going for a walk, he would be exhausted from a long day and generally fall asleep on the way back to the apartment.
We did manage to get replacement parts for it fairly easily when we got home, and had it serviced to make sure the damage was only superficial to the frame. But very shortly after we sold it and got a maclaren instead, to which I have never looked back!! Obviously this is just my opinion from our experience with it, but I personally wouldnt recommend the zapp at all