Hi,
 
Since I have a bunch of gear sometimes something pops up, way way cheaper then before... But... will it do the job..
 
Now the new RME Digiface USB is such a device. Some rackmount pre's attached and you have a great portable solution. USB 
has never been very reliable latency wize. Since I have rackmount computers too...
Does this have latency on par with a HDSP9652... Or not?
 

The RME USB driver is rock solid on all the machines I have tried it on. 

I would take this to the RME Forum. Matthias is probably the one who will answer. I'm pretty sure the answer is Yes, but get it from him. He will have numbers.
https://www.forum.rme-audio.de/
 
 So far, I haven't heard any exodus from the RME owners to some other product. All of us are pretty happy. Usually. this means it works for us to do what we need. It may be that I can imagine a solution I would like more than my RME, but I've never seen something in use that I would rather have.

I guess it depends on how large your projects are and what latency you're shooting for.  I've been using the RME UFX via USB for years with projects of 75 tracks of 24 bit audio / 96 kHz at low latencies without any issues. 
 
As said above, the RME USB drivers have generally been very stable and perform well re: latency.  I suspect you'll hear similar feedback from others on this forum based on historical threads of similar discussion, but as gswitz says above, the RME forum will likely have the detailed throughout specifics.

Hi. I don't have the Digiface (have an UCX), but can testify that the RME USB drivers are top notch.
Stable with low latency.
I've had mine for close to 2 yrs ,with no issues.
All the best.