I think if you can be happy with your body just as it is, sags, bags or whatever, that's great, and certainly a healthy attitude.
I however knew long before surgery that I would not be happy with a panni or fat arms. My panni ended up being just a long droop of skin with pretty much no fat in it. It affected how my clothes fit and how I felt in a swimsuit as well as in intimate moments with my husband. For me, abdominoplasty was worth it.
I never have gone back to get my arms done, despite the fact I had an extremely easy time recovering from abdominoplasty. Part of it is money, and part of it is the truly ugly incisions that I've seen on many people--is it a worthwhile tradeoff? When I try to get some blouses on that have very slim sleeves (and I won't go sleeveless), I wonder.
I would estimate that 50% of the men and women who were in my support group and had surgery within a year of me ended up having at least one procedure, some had multiple. A few were and still are unhappy with the results, but most are very glad they did it. Only one guy who had a belt-line lift had any recovery issues.
Just my perspective.
Ann