2.5" PM830 Mobile/Client Edition vs A400:
Both use Sata Rev/Gen 3.0 which runs at 6Gb/s, which is the current highest.
PM380 uses 20nm MLC, while A400 uses 15nm TLC.
PM380 uses AES-256 encryption, while A400 has none.
Samsung uses an in-house controller while Kingston uses a rebranded Phison S11.
Samsung has an estimated 1.5million MTBF against 1 million hours MTBF of life expectancy.
The Samsung has a higher guaranteed Write Endurance (Terabytes Written) of up to 60TBW vs 40TBW.
Samsung is rated at Peak 500MB/s Read and 400MB/s write, against a baseline of 500MB/s read and 320MB/s write, but this changes depending on hardware, software, motherboard etc.
Overall, it depends on your needs. Is encryption necessary, or the 20nm TLC vs the newer but cheaper 15nm TLC? If you are a casual user then i do not think the better flash or encryption is needed.
The Kingston is not even 2 years old yet, while the Samsung is like 7 years old.
Performance wise, the Kingston has hit over 500MB/s in both read and write in tests.
Personally i would go with the Kingston.