I lost about 4 stone when I joined the police. I just wanted to pass the fitness test, this was my sole motivation for losing weight. I did hate the way I looked but at the time eating was my crutch and I didn't choose to lose weight for this reason.
After I got in I continued to maintain my new healthy eating and exercise habits (roughly - obviously with bad periods of laziness/overindulgence etc) and after I had my children I lost weight quickly and am currently the lightest I've ever been as an adult (I'm 40).
The pros are -
-not fretting about buying clothes anymore, I used to break out in a cold sweat if I needed new clothes, especially jeans, and would often cry on a shopping trip as I couldn't fit in hardly anything.
Now I can chose any shop and buy nearly anything.
-no chub rub in the summer. Used to avoid skirts and dresses as my thighs used to sweat, rub and hurt after walking.
had proper burning pain and red rashes in hot weather and skirts. Awful awful awful.
-I'm not at all a stylish person, but I no longer worry about how I look. If I put jeans and a top on I will be roughly happy with my appearance all day - when I was fat I'd be constantly pulling my top down, making sure my fat wasn't showing, hated showing rolls through my clothing etc
Now I know I'm slimmer and feel more confident.
-feel a lot more healthy. Don't pant walking up stairs. Feel confident of my physical fitness and future health.
-Don't feel guilty for having an overindulgent day/weekend, before if I had a fatty weekend I'd beat myself up.
Now I just go for a bike ride or run and continue to eat well and my weight usually returns to my normal weight range quickly.
I still use MFP after a longer period of inactivity or overindulgence (usually January!) for a few weeks to keep me eating healthily. I like exercising so this combined with better eating habits really helps me maintain a healthy weight.