I went between catholic church and protestant church myself, the one thing I can say about protestants is that they are more loose but that they represent idolatry less in the sense unlike catholics who have idols all over the churches, praying to Jesus, praying to Mary, praying to saints, etc.. I didn't find the same in protestantism. If you go to a protestant church you will not find idols like you will in catholic churches.
None the less both teach and ascribe to the trinity end of story. And both have man made things. The thing is catholics are more strict in preserving what they 'believe', while protestants well.. change. Protestantism was born out of recognition of the corruption in catholicism.
Buying your way into heaven was a big one. Literally paying priests to 'enter heaven' lol. How brainless people are to fall for crap like that. Of course that was in medieval times not today but still.
I personally felt more comfortable in a protestant church than a catholic church. Catholic churches felt 'ritualized' with pagan stuff (which it indeed is) and all the idols etc... it just didn't fly with me. Protestantism you could debate but then they became too lose in belief.
None felt as the word of God but quite clearly the work of men.
My family and I used to be all members of the united church of canada. We even had our own photos in the church book

Kind people, we still keep in touch with them, but Islam is the truth.
There are just so many offshoot branches its hard to keep up...
If anything I found catholics far more endorsed in the whole holy spirit, son of God ordeal than protestants themselves. They were adamant over it hence like I said very strict and form on trinitarian beliefs not that the protestants weren't.
I also remember with my catholic school going to a school field trip where we had people 'talk in tongues' to us. I 'fell to the ground' (faked it -- i dunno i saw others doing it so i felt inclined) lol.. later we found out they injected some of the girls with some drug and that's why they fainted. I was like WOW AM I GLAD I FAKED IT LOL
Sorry to dissapoint you again MOS, but unless protestants are now also non-christians, I don't know who's left to be a 'true christian'.