Stray Travel/ Kiwi - Hop on/off Bus Tours

<p>Does anyone have any experience with these types of bus tours for the 20-30 crowd, specifically in New Zealand? My D is considering buying a pass (good for a year) for one of these tours in order to do a backpacking trip with a bit of structure and the opportunity to meet travel companions, since she will be alone. Thanks for any information.</p>