It's old, and it's come down in price to $1500.  
Still it seems pretty awesome, and definitely better than the Focusrite Scarlett 18i20 I'm using now.
I generally use the pres in the rack or my Audient 800 going ADAT through my interface.  
The RME will give me 4 more great sounding pres, plus all the dsp fx and the amazing software mixer.
 
I'm primarily interested in lower latency and stability.
Anyone have strong feelings about this?
 
 

When you get RME sound card you have the diamond.

Strong feelings? Yes, it's super stable and sounds wonderful. It'll free you to focus on making music.

you can get the ufx for the same.
https://www.sweetwater.com/store/detail/FirefaceUFX?adpos=1o2&creative=55225946401&device=c&matchtype=&network=g&product_id=FirefaceUFX&gclid=COGlydby7NICFQsDhgods6MHTA
 

ARRGG!  I MEANT the UFX

Have a UCX ( similar ) --been very happy and RME driver stability is excellent. Totalmix simply works as it needs to. Happy RME user here. Good luck on the decision!

Congrats if you can afford this interface,
heard a lot of good comments about the sound and the latency of this unit.
 
I ´m also thinking about  getting a RME interface .
One question about the firewire port  :
 
Are the firewire RME interfaces  able to run via a  thunderbird port?
 
The basic question for me is if the firewire port is  
still a good choice for an audio interface ?
And USB 3.1 is arround the corner.
 
That´s why I would prefer a PCI-E Interface.
 
 

Hi. I have the Ucx, the little brother.
I am very pleased with it. Low latency, and super stable drivers.
I use mine over USB 2, with no issues at all.
 
@ Pragi Not sure if it works over TB, but USB(2) will not be a bottle neck.
Unless you are recording a massive orchestra, with all separate mics..
All the best.

Hello Zargg,
thanks for the response .
Good to hear that  USB 2  is no bottleneck
for the RME usb interfaces.
Bottlenecks I like  for guitars only.....
 
My question is more based of the future compatibility
for the next 10 years.
Spending  that much money for an audio interface
means to me that I like to have that unit as long as possible.
 
I ´m running my good old Focusrite saffire now for about 10 years .
The Firewire port was announced as nearly dead since that time
(f I remember  right 2008 ).
 
 
 
 

Blix : If you use it using the 1 x FireWire 400 port it will perform quite well ...but do keep in mind everything has gone Thunder Bolt lll and the power of that port is to die for..and is the standard !  good luck