Should I take the plunge and get the iPhone 5? (From a rMBP owner, lover of Windows Phones)

Just to start off, I am not trying to flame bait between WP and iPhones. I am just here to get serious advice about whether or not I should make the switch. I know very little about the iPhone so excuse my ignorance.

So by the end of January mine and my mom's contracts with T-Mobile will be up soon, and for the most part, I was set on the Lumia 920. It's all objective, but for me, I love the Windows Phone. I agree that the complaints against it are warrented, mainly the lack of apps. However, just recently, I've been slowly coming around to the idea of the iPhone.

Here's my situation; I own a rMBP and an HTC Radar 4G. The Radar was through insurance because I broke my other phone, so it's not the best WP on the market but it's decent. Before college I was planning on getting the Surface Pro, but I found out it wouldn't come out until January and I couldn't wait that long, so I ended up spoiling myself and bought the rMBP. I absolutely love this laptop, it's great...but I don't think I'm getting the most out of it in terms of the whole "ecosystem". I realize that, owning a Microsoft and an Apple product, I wouldn't get the most out both phones that I could. I was fine with this until recently, and now I'm open to change. However, I would need a couple of things cleared up for me before I decide what to do.

Size
The whole argument with the 920 being too heavy or large doesn't bother me because I have massive hands. In fact, I prefer my phone to be large so that it feels more comfortable in my hands. I know that with the 5, the screen has been stretched, but how does it feel for people with big hands? Is it comfortable? (Just to put into perspective, with the F keys used as actual function keys, I have to do the whole "fn + sound volume" to change (pardon the ignorant tech terms!) and I can easily do this with one hand when turning the volume down)

OS
We can argue all day about which OS is better, but for me, I love the OS on my WP. I love the tiles, and I love the integration with facebook with messaging and calendars and the photo/camera section. What is it like with the iPhone? Can I do the same thing on it? This is just me, but I love being able to press the search button, type in "Cinemark" or "Best Buy" and it automatically comes up with all the locations in my area and the integration with the maps. How is it like on the iPhone? Better? The same?

Maps
One thing I do love about the WP is the maps. I really like the Bing maps (I know, I could use gMaps which is probably better but I'm lazy), and I haven't had a problem with the turn-by-turn directions, finding addresses, etc. I also like the "Nokia Lens" option in the 920. I know that there was the whole issue with the Apple Maps, but that was a month or so ago; has it improved any? I live in a big city (Houston) so I doubt that I would have as many issues as other people, but for anyone in Houston, what is your opinion of it?

Carrier
I know there was an article recently posted about choosing a smart phone and to choose which carrier, but I'd like your opinions as well. If I were to go with the 920, I only have AT&T to choose from, but with the iPhone, it opens up more possibilities. Of course, I won't have much trouble with LTE since I live in Houston so the major carriers cover it, but for those living around a big city or here, which carrier would you prefer?

Apps
I know the iPhone has the most apps, so my next question would be, if I were to get the iPhone, which are the best apps available?

To wrap-up, what would be your opinion as to why I should choose the iPhone over the 920? How much "integration" would I get with the iPhone and my rMBP?


Sorry for the long post. I just want to get everything sorted out before I make my decision. Thanks for reading!