Matt,
As someone who's been in for about 4 years now, I'd definately say that it's worth it. The flying rocks - especially on ops, despite the obvious disadvantages of being away a lot - and I don't know of anywhere else where they pay you so well to do a hobby.
Agreed, there is an ever-increasing level of frustration at the continual erosion of the few remaining benefits (see the MQ thread on this forum for a good example) but I think that 90% of aircrew will freely admit to not being happy unless they've got something to moan about. After all, if it really was that bad then we'd all leave.
No doubt it isn't as good as it used to be when some people joined up, but then not much in the world is anymore. As long as you go into the decision with both eyes open you won't go far wrong. As people have said above, beware of people on here who have been in for 25 years and are now jaded by it all, and possibly slightly detached from the reality of being a 1st/2nd tourist shag pilot on the front line (stand by for abuse!).
Any specific questions then send me a PM,
Regards, JJJ
PS - For interest, the average time away on the SH fleet is between 4-5 months of the year - it's bad but not that bad.