I have access to both Z10 and Jolla. Both are very nice devices and I don't think you can easily say "this one is better than the other" - it depends on your preferences. I find SailfishOS easier (and more fun) to use and the Android support is better, but BB10 is more robust and useful for work/organization purposes.

I would say Jolla is similar to the N9, just smoother - both have a simple calendar, e-mail, messaging. BB10 has much more advanced features than Harmattan/SailfishOS in this area, but not everyone needs it.

If I were to decide between Z10 and Z30, I would definitely go for Z10, as it has a better form factor, fits nicely in your hand.

If I were to decide between Z10 and Jolla, it's not an easy choice, but I have already decided - I am writing this on my Jolla But the choice is subjective - I appreciate the openness of Jolla, where you may never need to fiddle with the system, but still have the option if necessary. And I think that Jolla is more future-proof, but it's just my opinion. It would be very nice to have the Hub and advanced PIM features on SailfishOS, though...