Brady,
If you do a search you'll find a few other posts on the subject.
I've kited there and the beach break can be punishing to get through - but if the sandbanks slightly offshore are working it can be good fun (often the best banks form when the sandbar across the river mouth has just broken)
Couple of points;
Before the wind gets strong there can be many many kids and families there + dogs on the river mouth beach. Don't rig up where they are or we'll get banned. As you will have seen there's 20km of empty beach north and south.
I've seen kiters occasionally on the river in a strong seabreeze - but there's not much room and it's not ideal.
And one final thing - the State Government (Alannah MacTiernan) has recently done (IMHO) a fantastic thing and rezoned the land to rural where there was a proposed 5000 home housing development by the Plunkett family

.
The developer is appealing the decision - but I think it's over for them.

All that beautiful area to the south would have been ruined (including the dunes onto the river).