It would be awesome in terms of control and security, even better than an no rooted Android device.

I see all opinions come from Z10 users but none is from users of BB with physical keyb, such as Q5, Q10 or Classic?
Would work the cursor touchpad of a BB Classic with Android apps?

If BB and/or Jolla can implement fine grained[*] permissions that overrides what the apps asks for (and they always asks for far more than they really need) then that would be a huge selling point for people who value privacy and security but still want to run the occasional android app but without the android baggage (ie google play services which uses up half the available memory, and your device manufacturer's own "services" that takes up the other half of your memory).

[*] the standard android permissions are too loosely defined, eg apparently to get access to the camera's flash LED (so you can use your device as a torch) you need to give access to the complete camera infrastructure such that the malicious "torch" app and also take pictures and videos. Another example, some media players need the "access phone info" permission which they can use to determine when there's an incoming call and so mute or turn down volume of playing media. But the "access phone info" permission also provides (I believe), the phone number, the caller id, etc, ie stuff that malicious apps shouldn't be able to access if all they need to know is whether there is an incoming call. Plus when installing new apps, google has now dumbed down the permissions info dialog such that it doesn't show all the permissions an app requests.

Decreasing Volume, Muting, or Pausing... are things the App shouldn't be able to do. It should be the OS that's in control of the state the phone is in, and what actions to follow and allow.

It's always a balance between control in the OS and control in the Apps.

Too many controls/features in the OS, and you get bloat. The device can become less responsive, require more performance, cause more heating, drain more battery, look less intuitive. Think TouchWizz. The best Android OS out there in terms of features and control (well, excluding AllianceROM and PAC-ROM).

Too many controls/features in the Apps and you get "fragmentation". The device can be less secure, it might require many Apps, those Apps may introduce unneeded extras leading to bloat, it might become trivial to download so many Apps to do certain tasks etc etc. Think 4.0.3 AOSP. Is functionally identical to a 4.4.4 Nexus device. However, there's many little features the new Nexus/Stock ROMs include that aren't in the AOSP ROM. And to get that, one must resort to using MODs, Apps, or Xposed Framework.

What's my take on the issue?
I want my Android to be able to handle Health data, Security etc etc in the code. But that doesn't mean I (or the majority) would use it. So its better to keep a lightweight framework inside the code, but offload as much as possible to the App. So that I can pick up a brand new Galaxy S6 and it wouldn't have S Health, but getting it would be easy as 30 second App find&install.

And when I'm in the dark, and I want to quickly activate the device's Flashlight. I want to be able to do that by a basic gesture or by holding down the Home button. This is simple, useful, and should be in the OS. I shouldn't have to waste 30 secs to obtain such a understandable feature.

So its a balance.
Make it possible to make the device powerful/feature-full. But make it convenient to gain these features.
And leave the obvious/useful features baked in the device. AOSP is too light. Android One, Nexus, GPe devices are somewhat light. SONY and Motorola are well balanced. HTC, Lenovo, ZTE, Huawei are somewhat bloated. LG and Samsung have a LONG ways to go.

As bad as it sounds, Apple seems to be striking this balance fairly well, as iOS rather clean yet its very powerful with the use of the intended Apps. Usually the Apps themselves aren't too bloated either. So this balance doesn't just apply to Android, but to iOS as well as any other modern mobile OS. Jolla would be wise to always remember this.

I wish someone with with a BB Q10 or Classic told me his opinion about Android emulation.

In fact I would like to buy the Classic because screen size, touch pad cursor and keyboard but I need to be thoroughly sure that it will work fin with Android and the performance would be good for applications (I am not a gamer on mobile devices)

Sorry, I am kind of late to post this. I have a Q10 on which some android apps are installed. I am not impressed with the performance of android apps on BBOS. I found them laggy .

In comparison, the android apps on Jolla performs really great. They are snappy and works like charm.

If you want me to test any specific applications let me know, and I will check that..

I strongly believe the Jolla with TOHKBD will blow BBOS10/7 phones out of water . It will give you a great keyboard with configurable shortcuts.

I moved from Q10 to Bold 9900 because of the lack of shortcuts and then ultimately to Jolla and is totally happy with the move. Eagerly waiting to get my hands on the TOHKBD.

In my experience it's kind of a mixed thing. Some Android apps are running faster on my mum's BB Passport than on my Jolla (for example, the MSN Food&Drink app) but others are faster on my Jolla (for example, our national banking app).

@vistaus, h/w-wise bb passport is more powerful than jolla, eg faster cpu, more ram.

Has anyone tried with a Blackberry Classic?
I am pretty interested in know how the classic button are supported in the android emulation.

I am sure it will need to use some android apps, including typing and select, copy/paste, and the touchpad cursor is the best solution for it.
Anyone, has an opinion about this feature?

I'll reply myselft

Physical buttons of Classic are supported, in fact one of the is associated to the Android menu. Even direction button works fine in android apps.

Most android apps works fine, and specially those from the F-droid free repository

However those apps using the "Google play services" will not work by default. and some hack/actions have to be done. It is a pity that some developers are using this google closed features.

I have a few apps using Google Play Services on my Passport. I can just dismiss the "download the Google Play Services" dialog window and the apps work fine.