It's really up to you. These are the list of his plugins and what they do.
1. MMD Player as described
You must be registered to see the links
I guess this works ok. If you can find MMD files the girls do dance to them, and the camera does move, but it's really not worth the price of admission.
2. RenderToMovie as described
You must be registered to see the links
This IMO is EXCELLENT and allows you to make High Quality movies of your VAM scenes. If you're a content creator then this allows you to make excellent content!
3. RenderToVR as as described
You must be registered to see the links
This IMO is EXCELLENT and allows you to make VR movies of your VAM scenes. Unfortunately, it's extremely slow, but that's how VR is. If you're a content creator this allows you to make great content.
4. VaM Super Mode described
You must be registered to see the links
No idea how this works.
5. Looks Scanner.
This is very very rough. It goes through every single Var file and makes appearances from them. It's nice but there's no way to control which vars it goes through! IMO, if you don't mind having 2 VAM installs, you want to only run this on a new install with only the looks you want. It does work though.
6. FasterVAM
Yes, it does make VAM load faster. This is what most people are interested in, but IMO VAM should do this automatically, it shouldn't need a plugin.
If you're a content creator, IMO, it's worth it to buy a license, for just putzing around it probably isn't worth it. He has some DRM, so you can't really pirate this, though he promises to remove DRM if enough people support him on Patreon.