Reddit reviews The Brothers Karamazov: A Novel in Four Parts With Epilogue

Can't speak to the illustrated version, but with any Russian text I usually check if there's a Pevear and Volokhonsky translation, and go for that in the first instance.

It took me 2 tries to get into. Though I have only read one tiny part of another version, I read the entire book of this version. It was a pretty easy read for me after getting used to his style, of course. Though it took me a few months because I was reading at a slow pace.