Sony Xperia J reportedly and surprisingly getting Android 4.1.2 Jelly Bean upgrade

Quick, name three Sony smartphones still running Ice Cream Sandwich that you think would hugely benefit from a JB upgrade. Does anyone have the Xperia J? Probably not and yet the 4-inch mid-ranger (low-ender?) is being slapped with an Android 4.1.2 software bump as we speak.
Don’t get us wrong, we’re not complaining. After all, even the most modest members of the grand Android family need to get some attention and love once in a while. It’s just that Sony would have probably wanted to roll out JB to the Xperia S first. Or to the P. Not to mention the TX.
Oh, well, it is what it is and us bitching about it is not going to change a thing. Besides, you have to admit the prospect of seeing Jelly Bean perform on a phone with a single-core CPU and 512 MB of RAM is really, really intriguing.

What’s weird is that Sony is yet to come forward with an official announcement on J’s upgrade, meaning that it’s probably still limited to certain regions. Many J users are reporting getting JB OTA ever since last week though, so do take the time to perform a quick manual check for updates or fire up the PC Companion software.
Weighing in at around 392 MB, the thing will take some time to download and install, so make sure you have your battery above the 50% mark and an active, strong Wi-Fi connection. The new firmware version should be 11.2.A.0.21, the kernel 3.4, while Google Now, Project Butter and a series of performance enhancements and bug fixes lead the changelog.
Has anyone got the 4.1.2 bump on the J? Where, how, and, most importantly, how does the software look and feel? Is it everything you’ve dreamed it to be or is it clunky because of the low-end hardware?