I have been known to keep Motrin in my kit from time to time. Never considered Celebrex and probably never would although I have had it prescribe for me in the past. I figure the Motrin would be effective for reducing swelling or fever (pain I am willing to live with in a survival situation). I also keep Tylenol for reducing fever.
The biggest difference in COX-2 inhibitors and NSAIDs such as motrin is not their pain control or ability to reduce swelling, but that the incidence of GI bleeding was less with the COX-2 inhibitors.
That is almost exactly how my doctor descibed the differences/similarities to me. That is why for short term use he recommends NSAIDS and only prescribes COX-2 inhibitors to protect the stomach when long term use is needed.