I have both the SATA m.2 and the newer PCI-E m.2 and the PCI-E is 2-2.5x that of the SATA interface.

AttoBench shows the SATA model showed about 500MB/s r/w, whereas the PCI-E shows about 1GB/s write and 2.2GB/s read. Yes, it's noticeable. The PCI-E in RAID 0 is just ludicrous.