A lot of Android apps, even ones that run just fine on the BlackBerry Z10, fail miserably on the Q10.
I think it's because of the perfectly square screen - the hardware doesn't HAVE a 'portrait' or 'landscape' mode, so the app goes AUGHWTFBBQ and quits.
The other issue I have is that the hardware keyboard simply doesn't work in a lot of Android apps. Letters will type the wrong character, and using the Sym key to access things like the = is a real crapshoot.
All of which is extra-irksome because there are some apps which simply don't have a BB10 equivalent, even when there's a BB7 version. An AOL Instant Messenger client, for instance.
I really like my Q10 overall, but the Android sandbox still needs work.