[Nexus 7 (2013) General] sfhub:
JSS15Q factory images and OTAs available in Downloads section (below)

*WARNING* JSS15Q touchscreen firmware is a one-way street, no going back

*UPDATE* there is now a solution for touchscreen issues below

If you just want the GPS fix, see this post.

If you have touchscreen issues, see this post.

Apparently the JSS15J got pulled as folks who were on JWR66N and had the notification of the update no longer have the notification showing up. Also the downloaded ota update.zip in their /cache directory is no longer there.

Separately there are reports of a JSS15Q update going out which appears to be alleviating the multi-touch and GPS issues.

Let's discuss/consolidate peoples' experiences with JSS15Q in this thread so we can see what changed, got fixed, or was made worse.

You can see some comments from folks about JSS15Q alleviating Multi-touch and GPS issues at the bottom of these threads on google product forums:

Multi-touch - reports of improvement, no improvement, and some worse

GPS - reports of mostly completely fixed

Random reboots - no real success stories regarding JSS15Q

Initial impressions

For Multi-touch, it appears there are hardware variances which the software needs to account for. Some folks are seeing everything fixed, some people are seeing no change, and some people are seeing new problems introduced. So if you didn't notice issues is JWR66N but started seeing issues in JSS15J, this update will be good for you. If you already saw issues in JWR66N, then this update probably won't do anything for you. More recently there have been some reports of JSS15Q making touchscreen issues worse.

Unscientifically, most people are reporting either multi-touch is fixed or no change and a few are reporting it is worse.

If you continue to have multi-touch/touchscreen issues, see this post for a solution.

The specific change for Multi-Touch was the firmware was updated to A042. See this post for the whole sordid history of our touchscreen firmware.

Our touchscreen is made by Elan Microelectronics. See their Youtube video demonstrating their capabilities using of all things, YAMTT!

For GPS, most people are reporting that their issues with GPS losing lock after a period of time are now resolved completely.

For random reboots, no definitive info on whether there is any improvement.

UserData eMMC corruption seems to have been addressed, see this post.

It appears the PRNG vulnerability is addressed. See this post for more info.

See list of patched areas for places to focus on looking for improvements.

Facelock, GPS, NFC, Sensor, AAC encoding/decoding, and Camera seem to have the most changes.

Change summary:

JSS15J(4.3_r2.1)->JSS15Q(4.3_r2.2) AOSP Changelog.

Mini guides:

adb sideload (install OTA using stock recovery, no need to unlock, preserves user data)

flashing factory images (factory image restore, must be unlocked, option to preserve or wipe user data)

restore stock recovery (if you've installed custom recovery and want to go back to stock)

installing OTA-compatible root/SuperSU (will install SuperSU and fix so that it works with OTAs)

entering safe mode, bootloader, stock recovery (button press sequence can be tricky for fallen android)

Downloads:

JSS15Q

JSS15Q Factory Image (thanks roy827, poisike, Zylograth)

Source: pure stock - Format: flash in fastboot/bootloader

Guide: flashing factory images

Caveats:

requires unlocked bootloader

options to wipe or preserve user data

JWR66N->JSS15Q OTA (thanks Zylograth, Aerys)

Source: pure stock - Format: flash with stock recovery (adb sideload) or in TWRP/CWM

Guide: adb sideload

Caveats:

MUST be running unmodified JWR66N

If you are rooted with SuperSU, OTA will fail near the end. See this post for explanation/fix.

stock recovery does not require unlocked bootloader

preserves user data

JSS15J->JSS15Q OTA (thanks roy827, poisike, Zylograth)

Source: pure stock - Format: flash with stock recovery (adb sideload) or in TWRP/CWM

Guide: adb sideload

Caveats:

MUST be running unmodified JSS15J

If you are rooted with SuperSU, OTA will fail near the end. See this post for explanation/fix.

stock recovery does not require unlocked bootloader

preserves user data

JSS15Q repackaged TWRP/CWM-flashable

Source: slightly modified stock - Format: flash in TWRP/CWM

Caveats:

this is not pure stock and will not work with future OTAs

this is rooted, with unsecured kernel, and init.d support

odexed and deodexed versions

preserves user data

Factory images (direct download)

JSS15J

JSS15Q

Stock kernel/recovery

stock JWR66N kernel

stock JSS15J kernel

stock JSS15J recovery

stock JSS15Q kernel

stock JSS15Q recovery

Root/SuperSU

UPDATE-SuperSU-v1.51.zip - install in TWRP or CWM for root

UPDATE-SuperSU-ota.zip - install this after SuperSU to allow OTAs to install successfully

====

Update #1:

Paul Wilcox Google community manager writes:

Hi everyone,

As a couple of you have mentioned, there's a new system update that's started rolling out for your Nexus 7s. This update does address the touchscreen issues discussed in this thread. If you're one of the people experiencing touchscreen issues, please let us know how it's going after you've received and installed the update.​

Update #1.1

Paul Wilcox Google community manager writes:

Hi everyone,

Thank you for your patience while we've been working on this. As Justin mentioned, there is a new over-the-air update for Nexus 7 rolling out now that addresses the GPS issue discussed here. We look forward to hearing feedback about your GPS experience after you've received the update.
​

Update #1.2

Paul Wilcox Google community manager writes:

Hi everyone,

We understand that several of your have received the recent Android 4.3 update but are still experiencing touchscreen issues -- we're looking into it.​

Update #3:

If you are rooted with SuperSU, OTA will fail near the end.

See this post for explanation and fix:

http://xdaforums.com/showthread.php?p=44597339#post44597339

Update #4:

Watched pot never boils.

For those folks constantly clicking check for update hoping it will download, usually in the early days of a rollout there is a process that randomly chooses device id's that will receive the update. If your unit hasn't been chosen, no amount of pressing check for update will get you the update, until you are chosen.

After the initial rollout they turn it on for everyone.

Once the URL is available, you can manually download and install using stock recovery and adb sideload or, if you are more bold, using custom recovery, though IMO it is safest to use stock recovery for OTAs.

Update #7:

First XDA report of JSS15Q factory image resolving multi-touch issues

AnandTech says GPS issues resolved as well.

Some reports of update not helping with multi-touch [andrewNY / phazerorg]