Will preface with the disclaimer that ramses is way more knowledgeable than I on all things RME.

Had the Babyface Pro FS and it was wonderful to record with, sounded great. But I already have a Fireface UFX+; the Babyface was for portability. Did audio recording of dialogue and used a Zoom H6 at the same time. Even with dialogue the Babyface was quite a bit better in sound, noise from HVAC was less on the Babyface and overall clarity better as well. But the H6 won out for the portability and built in mic ability relative to the application needed at the time; they are very different units. Babyface is bus powered and works well with an iPad Pro and even an iPhone.

Returned the Babyface after trying an ADI2-Pro FS R Black Edition. Price point very different so that must be considered. The initial reason was better digital IO for my needs on the ADI2-Pro; Babyface works well with optical but for my external devices I did not want to use an adapter for SPDIF or AES. As for sound, I have been enjoying music from CD's (transferred to HD using dB Poweramp) in a way I have not since LP's on high end equipment 25+ years ago. The Babyface was great for this, but the ADI2 better. Both better to my ears than the UFX+, but both limited IO relative to the UFX+; apples to oranges from an application standpoint. The ADI works well for recording in the field with an iPad and iPhone as well, but not bus powered and not as portable.

If you have external mic/instrument preamps, then the ADI would be worth considering. I also have an API Transformer GT as a guitar interface and it does make a difference with plugins. It gives more of an amp feel going in than anything else I have used with plugins preamp wise except for a Kemper (which plays well with the SPDIF input).

Total Mix is great on the Babyface, much simpler for me. As ramses stated you may always add an ADI-2 later.

Having both would be great; I do miss the Babyface.

I'm using (original) ADI-2 for recording, editing & monitoring music, but have TotalMix (BF original and RayDat) as a base..would probably say go with the new BabyFace Pro FS, - then you'll be getting the best of both worlds, latest and fastest DAC..

There can be a huge benefit in using outboard pre-amp - something often forgotten is how well some gear sounds ran through a simple good quality mixer or simple tube-pre. I love having the ADI-2 on Hi Gain being able to get the full benefit of the dynamic range - but I have to go through the proper kind of mixer/pre-amp for this to work, and when paired up correctly, it's definitely a "Pro" experience

EDIT: Just saw and heard some reviews of that API thing "paulsfinney" got - exactly my experience too - get some good pre-amping going in before hitting the DAC.

What I mean is going from consumer level to pro level input and output stage - you gotta have the right pre-amping going in, or else the signal will be too low obviously. Nothing wrong with consumer levels, but now having "Pro" gear, I'm pleased with the difference Not sure how the ADI complicates things, it all depends how you look at it. Some just need to see the inputs in their DAW and do everything from there.

Sure, possible.

Pls consider:
- communication through ADAT takes as good as no time (mentioned by MC a few times)
- whether AD/DA conversion takes place on BBF or on ADI-2 Pro makes not much of a difference,
   D/A is even tad a bit faster with the ADI-2 Pro:
       ADI-2 Pro FS: 0,11 / 0,12 ms (AD/DA, DA Slow)
       BBF Pro FS:    0,11 / 0,16 ms (AD/DA)
   
As you can see, converter latency is in the range of fractions of miliseconds.
Depending on which ASIO buffersize you choose, the RTL (including converter latency) is in the range of 2,2 - 86,9ms.

For a few products and product combinations I made a list of the resulting RTL
(according to informations from the driver, which are with RME drivers always very accurate):

You can compare the different USB/FW/TB interfaces with my Excel sheet here:
https://www.tonstudio-forum.de/blog/ind … B-MADIfac/
Direct link to Excel: https://www.tonstudio-forum.de/index.ph … -04b-xlsx/

All AD/DA converter chips are nowadays on a high level.
A few DB SNR more or less and measurable, but not audible.
AD/DA Converter should perform an accurate ADDA conversion and not have something like a "better house sound".
The analog stage and the overall design is also important.
Like recording interfaces AD/DA converter are different in terms of features, whether they support DSD or different D/A filter.
I would trust RME here that they made a proper selection for each interface.
What has already been discussed in the area of ADI-2 DAC/Pro vs FS version: also its not cruicial to have or not have femto second clock, measurable better values, but not audible.
You are better off, to select your audio interface based on its features.
There is so few difference in converter latency between BBF Pro FS and UFX II that this should also not be your final purchase criterion. More important is to have the right amount of ports for expansions.
The four mic/instr inputs with 75dB Gain and features like Autoset and DURec and more powerful phones outputs and more support for different reference levels on inputs and outputs, two ADAT ports, AES, are more important.

Good choice and you can add an ADI-2 Pro FS R BE at any time later to get it's uniq features which adds to quality a lot.