Camera is eh? It's the best camera on a smartphone! :o It beats the Samsung GS4 and iPhone 5. How much better do you want?
Regarding Sense 5.0, I can't comment since I've never used any manufacturer skin except for TouchWiz. I've heard Sense was graphically bloated but that 5.0 has been significantly streamlined. Maybe it isn't so bad but when the Samsung apps on my S3 really bothered me and I can only assume the HTC apps will do the same. I guess I've been spoiled by a stock OS's.
As for the OEM skin, you can always remove that with a custom ROM if you don't like it. Removing the bloatware apps can be done with root, though I find most of them useful.
Sense 5 vs others? Sense 4 is when they REALLY started making it lighter and smoother. It's really smooth on my HTC One X with Sense 4, got much much smoother with the Jelly Bean & Sense 4+ update. Sense 5 looks even lighter.
As for a direct answer to your question, how long it takes between OS update and the next varies quite a bit depending on how much Google has changed the OS. For example, there were no ICS phones other than Nexus devices until like half a year later because of the significant overhaul. Sometimes it may take a month or 2, sometimes it could take up to half a year (only happened with ICS so far). But this is an issue with all manufacturers.
I understand you're bored with your current setup, but you have expressed that radically changing the hub of your connected life, your iPhone, was too big of a change. So I would recommend to get a PS Vita. It's expensive, but the games are awesome and truly different than iOS games. For me, it's like having a PS3 in my pocket. Yes it's another thing to carry around, but recognize that you don't always need it with you.
For me, PS+ is a great value because I own a PS3 so every month there are new "free" games to play. If you have an Xbox, maybe it's not as good a value, but renting a few games thru gamefly or buying used games will relieve you of your boredom.
Maybe for you, getting a bluetooth controller to try to play games with your iPhone 5 is a more economical option. I would stress looking for other/new apps, games and gadgets are a better option than giving up all the money you've spent in the app store, accessories you've bought and cables that only work with Apple devices.
I've had an iPhone since the 3G and wouldn't dare give up my iPhone 5.
Then again, you're too used to iOS.
Flashing would be like installing a new OS since someone has tweaked or modified it. It'd be the same as you running windows but choosing to install Ubuntu.
Rooting does add a layer of complexity since you essentially become your own manager of the hardware. Flashing can cause bricks or bring on tons of other issues. There are ROMS which are barebones stock just minus bloat which would be the least amount of headaches with flashing.
It's quite harsh to give up on the Galaxy S III because you did not like its UI - you can basically get rid of it, even without rooting your phone: www.theverge.com/2013/3/23/4132926/nexus-look-on-a...
The best Android phone I would recommend you purchase is HTC's One, which will reach US shores at the end of April, after numerous delays. I personally like it much better than the Galaxy S4, as its screen is second-to-none; the build quality and design are absolutely brilliant; the software is great, with a Flipboard-esque Home screen (though, as I noted before, you can easily use any launcher from the Google Play Store to get different forms and functions); the stereo speakers (BoomSound) are phenomenal, you won't need any portable speaker to get louder and better audio; and the camera is terrific for what it is (I mean, will you ever print out a photo you took with your cellphone onto a gigantic canvas? It's good enough for even playing back on a large, HD computer-monitor).
If you did not like the One, or the Galaxy S4, for that matter, maybe you should wait for the next crop of Windows Phone devices. Or you could stick with your iPhone 5 and look where iOS is headed.
As I've previously stated before I'm in love with the aesthetics of the HTC One but I'm not sure of the OS. Perhaps a simple launcher will change my whole perspective but I feel the safe bet is that I go with a Nexus 4 as my first Android device. Remember there are 2 things pushing me towards Android:
- A new "fresher" OS
- A BIGGER screen
I'm thinking it's this because that is where I'm at myself, I'm just need something new and refreshing that isn't say Smart Scroll.
I've been doing extensive research on Android and their flagship phones but I really can't make up my mind. The Nexus 4 seems like the perfect fit but the lack of LTE and the battery life is something I don't want to give up.
The DNA a great phone and the HTC Sense was not as bad as touch wiz (at least in my mind) but the biggest problem for me with Android phones is Verizon (my carrier). With the iPhone its pretty much the same phone on AT&T, Spring as it is on Verizon (software wise).
Have you considered a Nexus 7 tablet? Or even the Nexus 4 which are booth reasonably priced and you won't affect a contract if you are on one. that is assuming your carrier supports the Nexus 4. But either way a tablet like the Nexus 7 may be a good way to get your feet wet on Android and still keep your iPhone.
with that in mind i did order the Google version of the S4. i like the specs on it and like the fact that i will be able to change most of the software option on the phone by installing what i want.
Also for the S4 i like the add on items you can get from Samsung like the different cover option, the different batteries you can get for the device and the micro SD card slot that the One doesn't have.