Hi Andy.
I hope that we will be heading to Upper Hutt also, as thats where my big sister and her family live.
They live in Trentham and love it, she has advised Trentham and Wallaceville are nice areas to live in. She's also recommended Totora Park (quiet with a large Mormon population - a lot of young families).
I sometimes ask her about other areas (Upper and Lower Hutt), and she has advised that Maoribank,Timberlea, Clouston Park and Brown Owl are all older more run down areas with large ethnic populations (usually with some Gang houses in the neighbourhoods. There are some nice pockets in these suburbs and Brown Owl is the best of the four.
Hope this helps.
Kiwijo