I was in Christchurch for most of the week. I was staying at the Ibis in Hereford St. 

It's a short walk from there to the Metro Bus Terminal a couple of short blocks down Colombo St. All major bus routes (and virtually all the minor ones, too) in Chch go through the main terminal. 

The frequency of the main (Blue, Orange, Purple Yellow) routes looked to be very good through the day: about 10 mins apart. 

The fares are zoned. I wasn't really paying attention to the pricing. Everything I was doing seems to be $2.50 on my the Metro Card ( I bought it for $10 at the main terminal after checking into my hotel). 

The fares seems to be capped at $5 / day. That was cool. 

Yesterday, when I went to the airport on the "29 Airport via Fendalton" bus, I had already used my $5 for the day going to / from work down Colombo St on the Blue line........so my ride to the airport - dropped at the front door - was no additional charge.

The cab fare is $50.

So my transport for the whole week - including the trip back to the airport (took taxi into the city on arrival) was $40 - including $10 to buy the card, which I can now use every time I go to Christchurch.

I was impressed. OK....the route info and bus stops aren't on Google Maps. but the Metroinfo.co.nz web site has a very useful trip planner that looks OK on a smartphone.

I could have rented a car and ended up with the usual parking hassles and I could see some serious traffic blockages as I moved around that the bus didn't have to worry about due to bus lanes. 

I'd recommend anyone in Chch for a few days who is staying / working near / on the main roads / routes have a go at the public transport. It was cheap, convenient and reliable (for me - mileage obviously varies).