pros include nearly zero maintenence (my #1 reason, as im a lazy fuck) teaches good cadence, builds better muscle (forces you to pedal up a hill in a less than opimal gear) and a totally different feel on your bike than a traditional bike. also, if you know a little, you can convert an old frame into a fixed bike for very litle money. nice road bikes are expensive as hell, and you need to know way more to do your own maintenance. (if you need to ask why doing your own work or building your own bike is good, i dont think youd understand the answer.)
cons include hills (up or down) being sucky, the first 5 minutes on one being weird and uncomfortable, and high-horsed people who think your an idiot/hipster/trend jumper because they dont like your bike. now, i understand the scene behind fixed gears, and also think its a little humerous, hipster kids with purple chains, tight jeans, and pbr tee shirts and all... but fuck guys, really? nobodys ever said "oh a skier? so youre into neon onsies and apres wine? gaaaayyyyy!"
I can personally attest to the "i dont understand it, so ill hate on it" scene for fixed gears (call it a fixie if you want, whats gonna happen? some kid on the internet gonna make fun of you?) i delivered sandwiches at purdue on my bike. 2 other dudes delivered on fixed gears. i always thought it was lame, gave them shit, why wouldnt you want gears, all the shit those above me said. one day i blew a tire on my bike, and one of the fixed dudes was just getting off his shift. he had a brake on it, and let me borrow it for the shift so i didnt have to go home and patch my shit up. i was a little skeptical, but accepted his offer. only after i had spent a few hours on one did i "get" it. i could spend a while going into the "zen" feeling, or how it just FEELS better than a coaster, but that kinda stuff doesnt matter to those who have never tried it. most are to affraid of looking gay. news for ya: people will hate anyway, so do what you want. whens the last time someone told you skiing was gay and you took it to heart? or aligned yourself with the skiing stereotype of fur boots, finger-sandwiches around the fire place, and cheese platters?
TL:DR dont ask others for advice on shit you will like. because people are irrational idiots when it comes to things they personally dont like or understand. go try it. if you find it to be gay, like these articulate and well rounded folks on our beloved NS, good for you, you formed you own educated opinion. if, on the other hand, you find it soothing, smooth and a great feel thats different from the bikes youve been riding since you were 3, good for you, too.