Unpopular opinion: SSJ4 sucks
I'm going to get shot with millones of bullets and going to be 10 feets under but I have to say it or nobody will, SSJ4 in my opinion is a mid to bad form, I get that everyone likes how raw it is and I will have to admit that it is pretty raw and cool looking, but going beyond that it just has nothing else to it, for 1 it doesn't feel like a Super Saiyan form, when you put it side by side to all of the other SSJ transformations it just looks out of place, I feel like it could work as a new hybrid great ape form but as a SSJ form? Not really at least to me
2 the form is generally just bad, it has absolutely no build up, doesn't make sense at all, and is a literal un earned asspull, and again it doesn't make any sense as it's a form that is obtained via becoming a golden great ape and controlling it, problem is that we already saw characters like Vegeta control his great ape form yet not obtaining some sort of new form like SSJ4 and even worse is baby literally becoming a controlled Golden Great Ape yet he doesn't become a SSJ4
3 the form isn't unique like at all, the only thing that is unique about it is the design but other than how I explained earlier that the design makes it feel out of place there's also the fact that it has nothing else unique about it, no additional powers, no unique effects, hell not even a unique aura it's just Ssj3 but red tint, and overall it just feels like a less inspired SSJ2
On a final note, I'm not saying you shouldn't like it, I myself think it's cool and try to ignore how it's not a good form, you have the absolute right to like whatever you want no matter what it is, I genuinely mean it when I say that this one, SSJ3, and SSJ Rage even though being mid and having huge problems are still really cool forms