I’d say Neutron 4 and Ozone 10 Advanced both are interesting, but maybe not more than $50 each interesting, if you already have Neutron 3 and Ozone 9 Advanced. I even prefer the older GUI.
And another downside is the fact that Ozone 10 Advanced can’t be used standalone.
I considered the upgrade to MPS 5 quite worthwhile, as it also includes both Exponential Audio reverbs Stratus 3D and Symphony 3D (and all major iZotope software).
I’d say the best reverb deal ATM is the iZotope Holiday Bundle ($49 at PluginBoutique). It has that amazing Exponential Audio Stratus, plus Insight for metering and Ozone Elements as well as Neutron Elements.
A bit late, but I got Augmented Grand piano, FX Collection 3 and Dist ColdFire. I have to say that Arturia has upped their game to the highest level of plug-in devs IMO. For me, they’re up there with FabFilter and UVI.