I visited New Zealand 9 years ago with 2 friends for 3 weeks in late November, early December. We visited on our own both North and South islands with the mandatory ferry crossing from Wellington to Nelson. We stayed in backpackers and drove a few hours a day and did short hikes during the day. I almost liked every bit of it, especially the South island, you can see beautiful and diverse sceneries doing only short distances. Tongariro crossing was already packed. That being said it is a very long journey from Europe, not sure if I'd go back there again (now that I visited it). For fjords I have been told that the Norway's ones are more impressive. For lakes, pristine forests and glaciers, I preferred the Canada's ones (Banff National park). And for Alpine sceneries, well I know live in South of France and there are comparable sceneries with large plateaus dominated by snowy mountains, it is just wilder in NZ.