Cakewalk + Apollo - Is The Combination Stable For You?

Recently jumped from my stable and boring (in a good way) RME UCX to the UAD Platform.
 
To sum it up, it's been a bumpy ride. 
 
Got a Silverface FW Unit working via Firewire pretty nicely.
Same unit w/ Thunderbolt add on was a trainwreck.
Currently trying a Twin MKii via Thunderbolt. Much better, but still dropout prone.
(Especially instantiating VST instruments such as Addictive Drums, Addictive Keys and others; auditioning patches also brings on dropouts; some just while doing basic things).
 
Here's the kicker: UA support seems to be pointing the finger at SONAR/CW. They say Sonar's efficiency at a code level is not as robust as others. Sadly, I have to admit that Presonus Studio One Pro 3.5 is on my system and plays much better with the Apollo hardware.
 
So my long winded question:
Do others have Apollo hardware working well with SONAR/CW or do you find the pairing to be "finicky"? Are you running FW, USB or TB?
 
(obviously system specs/config play a huge role here: Quick version: New i7-8700, Asrock H370 Pro4 with TB Add In Card on MB)
 
Jim Roseberry has already been kind enough to weigh in on this and I'm leaning toward paying for his consultation time to give a look at my system to see what I may have missed (his expertise is substantial and well worth the $).
 
Any past experience from the user base in general would also be greatly appreciated!

BenMMusTech
I'd say look at the add on card. Back in the old days, Presonus units use to not work with certain Firewire chipsets. I think I've read something similar happening with Thunderbolt chips.

Thanks..and yes I'm definitely eyeing that card. 
 
Prevailing logic is "use the TB card designated for your motherboard only".
So I'm using an Asrock card approved for my Asrock MB....but I can't be sure it's not a wonky card :)

dcmg
Recently jumped from my stable and boring (in a good way) RME UCX to the UAD Platform.
 
To sum it up, it's been a bumpy ride. 
 
Got a Silverface FW Unit working via Firewire pretty nicely.
Same unit w/ Thunderbolt add on was a trainwreck.
Currently trying a Twin MKii via Thunderbolt. Much better, but still dropout prone.
(Especially instantiating VST instruments such as Addictive Drums, Addictive Keys and others; auditioning patches also brings on dropouts; some just while doing basic things).
 
Here's the kicker: UA support seems to be pointing the finger at SONAR/CW. They say Sonar's efficiency at a code level is not as robust as others. Sadly, I have to admit that Presonus Studio One Pro 3.5 is on my system and plays much better with the Apollo hardware.
 
So my long winded question:
Do others have Apollo hardware working well with SONAR/CW or do you find the pairing to be "finicky"? Are you running FW, USB or TB?
 
(obviously system specs/config play a huge role here: Quick version: New i7-8700, Asrock H370 Pro4 with TB Add In Card on MB)
 
Jim Roseberry has already been kind enough to weigh in on this and I'm leaning toward paying for his consultation time to give a look at my system to see what I may have missed (his expertise is substantial and well worth the $).
 
Any past experience from the user base in general would also be greatly appreciated!

Well, RME is the best! But to answer you question, no I have never used the Apollo.
I currently use the FireFace UFX Plus, and I can bet my life on it. 

I've been running an Apollo Twin Duo USB with my Win 10 Pro x64/i7 DAW rig for several years now without any issues. Very stable ASIO performance with a variety of x64 DAW apps (SPLAT, CbB, REAPER, Studio One, etc.). I also have a Satellite Octo and (2) UAD-2 PCIe cards for a (15) DSP farm using the Apollo Twin as my main audio I/O. I have not needed to reach out to UA or any forums for UAD related support, it just works. I suspect the OP's issue is more to do with having/maintaining a stable TB connection (TB card?) than with the Apollo TB drivers. If the TB connection is flaky it will adversely affect Apollo TB performance.

I use an Apollo Twin USB for my office computer and a PreSonus Studio 192 for my main music computer. No problems with either one.
 
The only way I would use Thunderbolt at the moment is with a Mac, but even then, there are TB1/2/3 compatibility issues. Many, but not all, can be solved by adapters. 

I use the Appollo 8 FW with an older win 7 system. I had done a little forum searching and found an older post that recommended changing the configuration file to ( MAx thread count  - 6 ) . I'm not at my DAW right now and can't recall the exact line in the configuration- but it worked for my set-up. Been glitch free and rock solid ever since.