I decided to get an N. macrophylla from Andreas, and I have to say that it convinced that it is the real thing. It fits the descriptions I've read and seen, and other smaller plants from other sources. It is very vigorous and never slowed down since I received in November 2010. I know someone else who has a much larger clone from Andreas, and it is definitely a N. macrophylla.
I feel that I have to say that in my experience, Andreas has sent very good quality plants. Sure some are on the small side, however they have all been very healthy and survived. I say that is what you pay for more econominic prices, I recently recieved N. tentaculata, N. tenuis, and N. artistolochioides from him and I was very happy with them.
I also know that he honours his customers when they claim a plant arrived damaged or dead by replacing them. It is very hard to control conditions once you drop off a box of plants to a courier, it is no longer under the watchful and careful eye of an experienced grower.
I just wanted to add my point of view from what I have experienced.