Teapos only have 2 series with low enough ESR to be used in PSUs. I'm guessing shuttle/FSP is using the SC series in there.
Teapos in general are bottom of the barrel stuff. They do OK in well ventilated PSUs, but other than that, they're just plain junk. Sure sign of cost cutting, or planned obsolescence.
Samxon GF are a well known bad series. LG liked to use them in their LCD monitor PSUs. Fixed so many of them over the years that I lost count..
The CX400 was a better unit overall, being basically a rebranded Seasonic S12 II.
The replacement CX430 is quite disappointing, even though it works out fine most of the time.
It's CWT OEM, i.e. the same guys that were responsible for all the failing Antecs about 5-7 years back.
The CX430 V2 is basically the same thing (and still CWT OEM), except replacing the Samxon GF with the GT series and a few modifications here and there.
I built countless systems with the CX400 without thinking much about it. Good bang for the buck and it was a Seasonic..
The CX430 (V2) .. meh.. better off going for a Delta Electronics based Antec EA-380D or 430D instead. The EA-380D has the exact same rating for the 12V rail (28A combined = 336W) as the CX"430".. go figure lol
I'm gonna stop posting about PSUs in here now.. getting a bit too far off topic IMO