Royalpurple fluids?

Has anyone changed all of there fluids over to Royalpurple?
(Both differentials, transfer case, transmission, and engine oil)

I recently purchased my '99 and will be changing all of the fluids anyway and wanted some input.

I knew a guy who did that and claimed he noticed an increase in power. Maybe, but if you ask me it is too expensive. Tranny, diffs, and t-case would make sense to use a good oil like royal purple because you don't need to change it often, or ever for that matter. But engine oil...I would just use a good synthetic like mobil 1.

Thanks for the reply.
It seems that the only way to get Royalpurple products around here is to order it. So, like you suggested, I'm leaning toward Mobile1 engine oil (because even Walmart sales it) and ordering the Royalpurple for everything else.

Off topic, but did you notice any difference in performance using the throttle body spacer and is the cold air intake loud?