I found 2395 harder as it concentrates just on periodic. The guy running the training centre thought new 2395 was harder than old 2391 also. The old 2391 was inspection and testing (which i find easy) & periodic (memorising GN3) it had a smaller percentage of questions on periodic so even less was needed to know about periodic to pass.
but thats just me, as i test and inspect regular and find it easy to recite what i do/would do in the real world. Where periodic takes up a small section in GN3, i found i needed to memorise in great detail that section as 2395 is mainly on that small section.
If you are good at memorising stuff, read GN3, memorise the periodic section and it should not be a problem.