There's an additional risk with the ISR companies--the contracts might dry up for Iraq and Afghanistan. Probably not in the next few years, but if you're planning on this as your ~10 year career leading into retirement it may be more of a factor.
If you do go that way, make sure to keep in touch with the people you work with that flow into other defense industry jobs. Getting the good jobs tends to involve knowing someone who can recommend you during the hiring process. Also be prepared to accept a job flying RPAs; they may or may not be the future of pax/cargo aviation, but they are absolutely the future of ISR.