intarray index vs gin index

Hello,
I'm trying to update my database to 8.2 version and have some problems
with intarray module. As far I know PG 8.2 contains many features that
are contained within intarray - indexing array fields (using gin),
operators etc. Currently (in PostgreSQL 8.1) I'm using intarray not only
for indexing (but this is the main feature) but also I'm using functions
(like count, sort...) and operators (+, -) that are provided by
intarray. My question is whether I still should use intarray for
indexing (if yes then either I should use GIST or GIN) or maybe GIN
index is faster than GIST+intarray / GIN+intarray.

Thanks in advance for reply.
ML