Been using them ever since they first appeared free a while ago (as do a couple of others here on NZFF that i know).
They are very good indeed. Parts of the texture set are still evident in the Summer time as well, particularly around hill country, and bushy areas.
In the Spring time they transform the look of NZ to a much more lush green as it really is, particularly around cities and towns, and bush and hill country, and also the grass around any non-photoreal airports takes on a much more realistic look.
From altitude, the textures take on a very nice 3D look, they really give depth to the landscape.
Also the pack changes some of the autogen buildings to buildings that look more natural here in NZ instead of the very "americanised" default agn buildings.
I think most that try it will like it. But, as ZK-LGD said, back up your original textures first, just in case you dont like them.
I like them so much, that i am seriously considering forking out the $$ for the full payware set with all seasons.
Lawrie.