I have both in 4u I've only used the venom for 5 sessions and in my opinion the nitrix is a tone down version of the 100zz.
The shaft is more flexible (still stiff) than the 100zz, giving it a whip effect which produces easier shots even when i miss time hits. it also doesnt tire me out after 2-3hr sessions unlike the 100zz (I would switch from the 100zz to a easier racket half of my sessions before i got the venom). Now for some sessions i would start with the 100zz then switch to the venom mid session because it felt similar and was getting tired from using the 100zz, and some i would start with the venom and switch to the 100zz mid way because I wanted more explosiveness and control.
The venom does have a damp feel compare to the 100zz which gives a direct crispier feel when hitting the shuttles. I had trouble peforming slices maybe because i haven't had enough time with it I'jm not sure, I tend to do different shot variations and the slices were the biggest issue for me. The 100zz produces stronger steeper smashes for me (my pov) and i feel like the 100zz is faster in drives and net play. The 100zz is better in control such as counterplaying netspins, drop shots and slices.
I've tried different rackets ( 88d pro 3rd gen, 99 pro 2nd and 3rd, axforce (80, 90 dragon, new, 100), Ryuga 2 Metallic and 2 Pro, Thruster Ultima, Claw Ultra) that could compete with the 100zz but i think the venom is closest to the 100zz in terms of peformance and feel, if the 100zz was a 10/10, i would give the venom a 9/10 in similar peformance. If you want the 80-90% of the 100zz peformance but dont want to spend big money on it i recommend the venom.