I tried a lot of distortions on my 303, and I always came back to the OG RAT. I know you lose accents and bass but it brings things out in the slides like nothing else I think!
Other folk love the MXR +, I had one for a bit and it’s definitely has more subtle range than the RAT. I always wanted more distortion out of it so passed it on.
I’ve never tried (but would like to) analog Renaissance/cask strength acid screamer or TSX303, both specific distortions for 303 that correct the issues of accent/slides. I think both of these are out of production though.