[Fire HD 8 and HD 10 Q&A, Help & Troubleshooting] richaardvark:
Hi there! Sorry for the delay - I've been offline for a few days. Hope everything went well/is going well! Happy to help if you still need any assistance.

To answer your two questions:

1) Do you know if the newest 5.6.2.0 can still be rooted if I were to upgrade to that one? I read 5.6.1.0 can for sure be rooted still, do you have any experience rooting 5.6.2.0?

- Yes! the current/newest version (5.6.2.0) can still be rooted. This is the guide I have used (several times now) to root my HD 10.​

2) If not (or unknown yet), in your opinion, what do you think it's the best firmware to be used on our Fire HD 10 in terms of experience (bugs, smoothness, crashes, ram management..etc)? What do you personally use?

- I definitely think the newest firmware is the best. Show Mode isn't really that amazing, but overall the latest firmware seems to be smooth.​

Beyond rooting, here are additional updates/enhancements/tweaks that I've found very worthwhile when setting up my HD 10 (gathered from the wonderfully bright and helpful people on this forum - just my own order/ and experience - shared openly with everyone in case someone might find this helpful):

Install Google Play Store.

Install a better launcher! I think some of the top/cleanest/currently most popular launchers are Nova Launcher, Action Launcher, Evie Launcher. If you want a "stock Android" experience there is the Google launcher. And also the Microsoft Launcher surprisingly isn't that bad/is well organized and clean overall. I use Action Launcher. Once you install your new launcher, and open it at least one time, then you can go in and disable Amazon bloatware and disable/freeze the stock FireOS "Home Pages" launcher, which will allow you to then choose your new launcher as the default launcher in settings. You have to open the new launcher at least once however and then freeze the Fire launcher/Home Pages.

Disable/freeze Amazon software you don't need or won't use. This is the thread I used to learn how to do this. But basically all you need is this spreadsheet. You can filter out all the programs you don't want to touch and then just copy and paste column B into your "ADB" command prompt/shell terminal (on your PC/Mac) and it will quickly disable them. If you intend to keep and use Alexa, be sure to read the descriptions and not disable any programs that she needs to run. Additionally, here is a new thread with an updated guide to disabling stock software - may be a better option, but I haven't tried it yet.

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Fix widgets in new launcher.

If your HD 10 has those annoying "Special Offer" ads on the lock screen, you can follow the instructions I wrote here to quickly remove them for good.

Install "Xposed Framework" - this allows you to have even more control over your device/various enhancements.

You can install Google Assistant if you want (I have it on mine and it works simultaneously with Alexa with no issues!).

Finally, I'd recommend some of the memory/RAM enhancement apps discussed here.

Other Helpful Tablet Setup Mentionables:

This is a good (root-required) app to quickly freeze and unfreeze apps.

This is my favorite file manager. And the root add-on. My other favorite file manager.

Lucky Patcher can be helpful to bring out extra features in an app, or to get rid of pesky advertisements.. If you're feeling completely unethical, you can get many cracked/free apps from Mobilism.org (you have to sign up to log in first).

You can generally trust that apps/apks downloaded from APK Mirror are safe/free from viruses.

If you ever need to test a downloaded file/app to make sure it is clean/safe, Virus Total is a very helpful, quick service that will scan your file and look for malware across many databases.