A general answer is that AlphaFold2 creates more reliable models than RoseTTAFold. This is based both on objective evaluations (CASP competitions) and anecdotal evidence (even though both papers came out 9-10 months ago, AF2 has been cited ~2400 times to ~560 for RF). The confidence scores you obtained agree with that notion, even though neither one is indicating a completely correct model. If there are long "floppy" regions in your model, they may be bringing the average confidence score down, while the rest of the model can be quite accurate. This is to say that the model may be globally correct, but with some poor local regions.

Beyond that, either method can be more accurate than the other on any given protein. It is impossible to give you a conclusive answer as we don't know anything about your protein or how the models were made. And even if we knew that, it may still be impossible to give a conclusive answer.

I mean...RoseTTAFold at least is relying on a physical energy function...in case of the uncertainty you describe I would still rely on Rosetta's result. AlphaFold (aka AlphaMap) has too much hype and it is biased towards stable structures. But I could be biased too hehhe... But have a look at: https://academic.oup.com/bioinformatics/article/38/7/1881/6517779