WP user wants a mid-range Android phone, help? [EDIT:Okay, I'm moving, help me out]

UPDATE: So you've convinced me, no idea why I stuck with WP for so long. So i'm getting the LG Nexus in just over a week and a few days. Any tips, information, apps or anything cool you wish to share, please do - I'm excited....eh.

I've been using Windows Phone since it launched. I've passed through the Mozart, Titan, Lumia 800, HTC Windows Phone 8S and am currently using the HTC Windows Phone 8X.

I currently have three mobile phone contracts, so another contract is out of the question - hence the desire for a mid-range handset, that I can purchase sim-free. Or, a high-end handset that is getting older, and can be picked up on eBay for a nice amount.

Why?

I really enjoy Windows Phone, but I'm bored. I'm sick of a lack of apps - not just the headliners, but apps that look nice and do things. Our Facebook application is pathetic - it rarely even sees an update.I'm also getting bored of WP, the lack of new features [that bring it on a par and beyond other operating systems, is also dull].

Not another Sensation.

Between the Mozart and the Titan, I decided to get the original HTC Sensation, for a lot of reasons, it put me off Android. I'd just moved to University and started a new IT job [networking], so lots of new things we're going on. I doubt I was in the right place to learn Android, the Sensation overwhelmed me, but underwhelmed on design and the camera.

The use:

-Facebook. [I need to manage our business page on the go, WP doesn't allow me to post updates, reply to comments or read messages sent to our page]. I also like the Android/iOS Facebook applications, they be good.

-Tumblr. [There's no tumblr app for Windows Phone - yeh, still.]

-Instagram. [Boyfriend just got an iPhone 5, all of my friends and colleagues are on instagram. I take a shit ton of photos on Facebook...I want to feel popular on another social networking site. No but, in all seriousness, I want to see what all the fuss is about]

-Whatsapp. [Again, I'm sick of 'metro apps', they're begging to look boring and above all else, WP apps lack functionality, here too Android's offering bests my current bore].

-Occasional texting/calling - as I'll be using my main WP device for calls, emails and texts.

-Access to Google Play so anything not on WP, I can grab and use.

Minimum requirements:

-Nothing colourful. I'm sick of colours. BLACK, maybe with a little grey. But hell the HTC One is pretty though.

-Good camera, well above shitty that is. Something that isn't going to hark me back to 'o6

-Nice screen - again we've been blessed with rubbish screen resolutions on WP for two years, and I'm not going back to 480 x 800.

-Nice design - not too thick, nothing too out there, just nice, reserved, simple.

-Update to date as possible in terms of the OS - I'm not wanting to be stuck in the dark ages.

-I'd be nice to play around with ROMS, never bothered to check too much about what you can do with them, but it seems fun, something I'd like to have a look into, but not too important, but you all seem to praise Android for it, so why not let me have a look.

-Price: Around the mark of a fifth gen ipod touch, either PayG or sim-free. So we're talking £200 or so either new or in great condition pre-owned.

What I've considered so far:

Xperia S

Xperia P

Dell Streak [a few months ago, so a no no, already ruled out]