Mobic and hips

Why is mobic better then save advil or aleve? I have a prescription but haven't started it yet. I have fibromyalgia and osteo arthritis in neck, shoulders, back, hips, knees and most recently my hands and fingers.
I have a long history of irregular heart beats(pvc's ) and I am reluctent to complicate them with added comlications from mobic. If soemone has info that would help I would appreciate it.

I have noticed that as my arms,hands and face are always in the sun all year around that they are very tanned as if I have been sun baking. I am also very tired when I take my tablet, I try to go with-out it when I can, and when I do I notice an increase in my energy levels. I have arthritis in my spine, knees,elbows,hands, wrists,hips and one shoulder, so I need to take the mobic tablets as they do seem to help, so I guess these side affects are fairly minimal,I have also noticed an increase in my weight, has any-one else experienced this also.