Sure! I wrote a pretty lengthy trip report on both islands on TripAdvisor:
north island: http://www.tripadvisor.com/ShowTopic-g255105-i403-k2760926-Trip_Report_North_Island-North_Island.html
south island: http://www.tripadvisor.com/ShowTopic-g255116-i729-k2760982-Trip_Report_South_Island-South_Island.html
We crammed in A LOT in just over 2 weeks - it was not by any means a 'relaxing' vacation - but who knows when we'll be there again. We're big into the outdoor/adventure type trips so this was right up our alley. A lot of people on tripadvisor did not recommend we do both islands, but I felt our trip was perfect for us. The north & south island are both so different & I think we saw what we wanted of each - of course there's a lot we also didn't see! We really enjoyed the volcanic area on the north, and learning about the Maori tribes. The rugged beauty of the south near Queenstown & Milford Sound is amazing. We spent some $$ to hire a private plane to fly us to Fox Glacier from QT - but it was totally worth it since the weather to hike the glacier is very unpredictable - we didn't want to waste our precious time there - & in the end the flight was rescheduled twice due to weather!
I've traveled to South America, Europe, Canada, & all over the US and have never seen a more beautiful place in my life like NZ. We loved it so much we even thought of moving there but then we would be so far away from our families. Let me know if you have any questions - sometimes I'm not on the nest for a while, so PM if you need to! If you're planning a trip I'm more than happy to give you tips, etc!