Hi!

Not a bad idea to switch over to RME ... ;-)

1) RME drivers are really stable in general.

2) Can't give an answer here, but I already heard about some issues with sleep mode. 

3) Yes, ADAT is an independent standard. Some users prefer clocking over word clock connections instead, but normally it works without any issues over ADAT. Of course the clock signal goes always only the same way as the audio stream. In my opinion it's worth to try out what master/slave configuration works better / fits your needs better. As far I know, in general MOTU devices work great as standalone units.

4) At least the UFX II is a great interface. It has 12 analog ins/outs and is expandable over ADAT (two ports each direction) and AES/EBU.

5) USB 2.0 simply is stable and fast enough for many audio applications. See here: https://youtu.be/dSIf4QGYs-c

So, you still have doubts … Ok … Some more to this topic.

TBH … what's the point of releasing, e.g., a TB interface if only a fraction of PCs and laptops support Thunderbolt?
In most, if not all cases, only the more expensive devices have thunderbolt support.
Keep also in mind that you can't simply upgrade a PC to Thunderbolt. I am very dissatisfied with such a design because I am used to, that normally, everything on a PC can be upgraded through PCIe slots with up to 16 PCIe lanes.

Moreover, I heard that a vendor cannot simply release a device containing a thunderbolt chip. Intel demands a licensing process for every device. Therefore, I do not wonder anymore why only a fraction of PCs and Laptops support thunderbolt and if, only the more "top of the line" products.

So, a recording interface that is exclusively based on Thunderbolt would only be usable for a fraction of users. A combination of Thunderbolt and USB3/4 would make interfaces unnecessarily expensive and add a complexity to the hardware which is not necessarily needed. At least not for RME who know how to write reliably and efficient drivers and FPGA based communication on the recording interface no matter what transport medium is being used.

I regard it as a big advantage that RME chooses, what's required, so that most users benefit from being able to use the interface for most computers and not making it unnecessarily expensive.

The max supported cable length of thunderbolt is around 2 m, that is not much, I require at least 3 m to place the recording components left from my desk and the PC on the right side. That is another reason against the usage of high speed interfaces which always result in shorter cable lengths.

Look at the former product MADIface Pro. RME can support 68ch (in and out) by using USB2.
https://archiv.rme-audio.de/products/madiface_pro.php
And you are worried about 30ch in and out over USB2?

The higher Bandwidth of TB/USB3 doesn't make the RTL any significantly faster, as you can see here:

I think there is also a difference in the type of data transfer when we talk about audio transfer.

The ASIO driver is instantly transporting data of all I/O ports over USB/FW/TB, no matter whether a port is in use or not.
This cannot be done any faster by as the needed bandwidth is fix and runs in a streaming / real-time fashion and depends solely on the number of channels, bit depth and the sample rate. Similar to a video session.

Higher bandwidth interfaces only would have a benefit if the type of datatransfer would be something like downloading a large file, where it doesn't matter, when exactly the packets arrive .. best as fast as possible.

But this transfer pattern you do not have with something like phone calls, video conferences and the transfer or recording and playback data from / to a recording interfaces.

What counts here is to have an uninterrupted reliable data transfer without too much latency
- inside of the PC, to be able to process audio data "in time" without loss (low DPC latencies, good drivers not blocking a CPU too long)
- for the transport of audio data over the transport medium without too much latency

Therefore, USB2 is fully sufficient and - as I mentioned already - RME uses no 3rd party communication chips on the devices that could be flawed by design to get most reliability and compatibility to the USB protocol standards.

There is a little advantage of PCIe/TB (external PCIe) at high computing loads and if you need to use smaller ASIO buffer sizes when a machine is under high load. But also this difference is neither visible nor significant even if you test with big artificial DAW loads, see below.

With Cubase, I created a project with 400 tracks and around 800 VSTs (two VST in each track).
https://www.tonstudio-forum.de/blog/Ent … cks-de-en/

Playback without audio loss was possible with UFX+ at the lowest ASIO buffer size of 32 samples at single speed and with the lowest number of samples at double speed (96 kHz) which is 64 buffers.
DRAM consumption of the project was around 26 GB.

I compared UFX+ through USB3 and a RME RayDAT (PCIe card).
It's the same excellent performance without audio loss during playback, and with about the same CPU consumption.

At the end of the day, you should also ask yourself why RME is known/famous for the driver quality...
Because this is since the beginning since over 20 years when we even had no USB3, Thunderbolt, PCIe.

As a side note … do you also have the same niggling little voice that tells you that you need an €8000 PC for recording with latest Threadripper 64 core CPU??? No, then think about why not. Is it maybe because such a number crunching compute power is in most cases not needed, and DAWs usually would not really benefit from a very high core count? In fact, what's in most cases more needed is the proper balancing of core count and single thread performance depending on your application demands. And this depends on how your DAW projects are. Some people only require little power for recording and mixing, with not too many CPU hungry VSTs. But some people use many inserts in a track or use CPU hungry VSTi.
Or do you feel bad that you have no 40 or 100 GBit switches at home? Well, you are not operating a data center.

It always depends, and you should try to see behind the curtain to get a better understanding of what's needed when and why. Don't stress yourself for no reason thinking, you would miss something if the recording interface doesn't use the latest high-speed communication standards.