Personally, I prefer accuracy over visual appeal. When both can be accommodated, that's great but if you need to pick, I'd go with accuracy.
I have only judged at a competition once and I don't know if it was by IPMS rules. Nonetheless, I came away with a big learning: if you have a sloppy build (seams showing, asymmetry, etc.) the judge may not even look at your paint. Some of the best paint jobs in our competitions get eliminated if the construction doesn't meet the first hurdle. Once you are convinced that the construction is sound, make sure your paint is cleanly applied (no runs, splatter marks, excessive build-up, etc). Once you re convinced of that, the replication of an uneven paint scheme should be supported by photos of you subject and stated on your info card. Having said all that, judges are human and you get what you get.
The final question you should ask yourself is: "Is this model for me or for the judges?"