Is it still worth to buy a N9? Indeed it is! The N9 combines a good hardware with a (unfortunately abandoned) amazing and flexible OS - but there are some bugs which won't be fixed ...

the pro's:
- good form factor
- amoled
- good camera (compared to Jolla and BB Z10)
- still active developers - openrepos
- still working Skype (nobody knows when meet follows symbian ...)
- offline navigation and most needed apps (we'll see what happens when the OVI store will close it's doors ...)
- highly customizable - search this site ...
- price ;-) - you'll get a used one in good shape with 16GB for a bit more than 100,- EUR (colored a bit more)

the con's:
- not everything work's out of the box - you'll have to do a bit of investigation and applying some patches
- the browsers - the stock one is awful - Opera and firefox are better in rendering and faster but outdated (no sync in Firefox and awful keyboard in Opera - and no security fixes ... )
- no maps updates - the latest are early 2013 ...
- no SD
- no HDMI-out
- no more updates for major apps (but sometimes fixes from the community as for exchange accounts)

well, that's it - finally if you want something not-related to MS, Apple or Google your options are limited ;-)

- Blackberry - I own a Z10 - it's a great business device - mail, contacts, messages, calls, ... all in the hub and managed to a nearly perfect workflow, telephone-calls are in real high quality and the OS is fast and easy to use - plus a real HDMI-out on the pro site (for me the only way I can play my mp4 movies on my girlfriends TV) and SD-slot - everything else ist quite boring - the android runtime is not as good as on the Jolla and the battery is *****, you can customize almost nothing and the stock media players are very basic (there is one really good in the BB World) - ah and the apps are really expensive - but it works and works and works ...

- Firefox OS - actually I never tried it because there was no hardware, that fits my needs (maybe the new transparent one ... )

- Jolla - I'm still playing around with mine, and it's a cool first device for startup - If you like spending hours in testing, playing with the OS, reading in forums and if you are willing to help a small company in supporting the idea of open source software on mobile devices, and if want to feel a bit more geeky than the guys with android ;-) ... buy one bit be aware, that you will finally use more android stuff than you expected because even the stock apps in sailfish are still too limited (email, calendar, ...) - the pro is, that much mire android apps are working on Sailfish than on BB 10.2 (haven't tried 10.3 yet ..) and SD-slot

- Tizen, Symbian, ... - even worse

So should you buy a N9? I would, but I already have one ;-) but I won't spend 200,- € - for a 16GB (130,- for a colored one made in Finnland in *mint* condition - 110,- for a black one) - you'll get a used Jolla for 160,- and a used BB z10 for 150,- - so it's more a decision of your preferences

So decide what you want ;-)
- a geeky enough, still good working device with a good support base: N9
- something that just works with no fancy and no blingbling and your day isn't longer than 10hrs (battery): BB Z10

- the future (maybe) and something totally different: Jolla

ah and if you want to stick with the major companies: still the best offer: Nokia Lumia 620 - good camera, small form factor, optional outdoor backcover, fast enough for everything, SD - but unfortunately MS :-(