I know a bit about them, and the target is completely different - PLCnext (and pretty much all of Phoenix Contact's product line) compete with current Siemens S7 generation, not LOGO. In practice, PLCnext is squarely in S7-1500 range and probably the bigger ones only.
That means heavy on Profinet usage, large powerful control units, considerable use of distributed I/O and multi-PLC operation, etc.