Every time there is one of these threads there is always so much misinformation.
Jailbreaking makes your phone ugly
This is ridiculous. Jailbreaking doesn't alter the springboard, except to add the cydia app icon (which is a handsome icon!). What you can do with theming can look good or bad. Totally subjective. I think some theming looks great, some terrible.
Also, with some effort, not advised for everyone, the vast majority of theming can be done without Winterboard. Then you can't complain about Winterboard issues.
Jailbreaking affects battery life
It really depends. If you jailbreak and have your phone fetching weather data every minute, run a bunch of tweaks/apps that are poorly coded, then sure battery life will be affected. If you take it slow and pick your apps and settings carefully, you will probably not notice decreased battery life. I had 30 or more cydia apps, themes with weather data, all sorts on my last jailbreak. I could not notice a difference in battery life.
Also, you think Apple code is perfect when it comes to battery life/issues...
Jailbreaking causes software/hardware issues
You know what... sometimes a beta jailbreak messes something up. Last time a beta version of limera1n caused an issue with my vibrate switch. So wait a few days and let others do the beta testing for you. Same goes for new cydia apps/tweaks.
It voids my warranty
Technically, probably does but I can't remember. But with just a modicum of care and knowledge this is not an issue. I have had hardware faults (screen issues and microphone failures) on phones that have been jailbroken. Just restore before you go back to the Apple store. I guess whether you feel that is okay is your own moral call. For me, I'm fine with it. But I'm only a pretty good person morally, not a perfect one.
But it doesn't do anything I want
Fair enough, that's fine. To each their own. But I bet it does, even just one small thing.
For me, I loath losing the ability to double tap the power button to play/pause. I don't have headphones (and won't) that have in-line buttons. So if I want to pause my podcast to buy a drink I have to take my phone out of my pocket, double tap the home button and press pause (sometimes missing the pause and hitting fast forward, arrgh!). And I risk dropping it every time.
And LockInfo!