I'm fairly sure the Samsung 850 EVO is still the best one for consistency during large file transfers, evne after running out of cache. The Kingston Hyper X Savage is also a good option, but yeah I haven't used all SSD's.
The LE is decent enough, but large transfers will get you to around 200 MB/s after it starts to write to the slower TLC-NAND, though the read still lands around 500 MB/s.
I'm not 100% sure about the ADATA, because people are just testing the cache, not large file transfers, say 8 GiB+.
Absolutely no difference between booting, gaming load times, normal use on any SSD that's fairly modern. You have to push an SSD to see the benefit of spending more money on one.
All the best!