What an interesting thread - I had a preventative septoplasty/rhinoplasty 23 years ago at age 19 for concerns similar to the blog link, and I was able to have cosmetic changes along with the 'fix the breathing' ones. I've never been able to compare with others' experiences.
Breathing pattern is mostly fixed - I still snore a bit in my sleep, and it's not apnea (been studied twice). I am still susceptible to upper respiratory infection, but nothing beyond the usual range of normal. I do generally breathe through my nose now.
The recovery was not that bad (I can now compare to ACL reconstruction - that was DEFINITELY WORSE - and gallbladder removal, which was easier). The worst bit of the nose job was the two weeks of black eyes ("you should have seen the fight!"), and the initial removal of the packing, post-surgery. Shades of Egyptian mummification ritual. Also, they didn't warn me that an amount of blood goes down your throat on the table, and that upsets your stomach, so you might barf in the recovery room, which looks just about as scary as you can guess. But was not an emergency. (This was my first surgery, and I didn't know that I generally get nausea from anaesthesia. Those airsickness stickers they adhere behind your ear do the trick for me now.)
I was given the instruction to manually press the sides of my nose together for a certain amount of time every day post-surgery, to help the new structure set up as desired. I guess that worked.
I've always wondered since if I really should have bothered with the cosmetic part - but I think it's a chicken/egg thing. If I hadn't had the cosmetic bit done, I wouldn't have gained the confidence to think now, "you know, you didn't really have to lower the bridge of your nose."