If you have time, I highly recommend taking the train. You pass through such beautiful scenery and you are quite comfortable. If you are lucky you may spot some whales passing through Kaikoura - we were not lucky. We did spot a lot of seals though. We purchased a KiwiRail 7 day pass, so we took the ferry from Wellington to Picton, and made a quick transfer to the Coastal Pacific - our luggage was checked in Wellington and we didn't have to worry about in our transfer, it was waiting for us in Christchurch. There are food options on the train, but they are quite expensive, so we packed some snacks from the grocery store. If you book your seats early enough, you can request to sit at a grouping of 4 seats with a table. Not a big deal, but nice to put some stuff out. All other seats do have a tray you can fold out.