I flat out don't believe that any IPMS judge has dinged an OOB model for having the seams puttied and the sink marks and ejector pin holes filled.
The OOB rules are very carefully spelled out for any IPMS competing modeler (and you don't have to even be an IPMS member to compete). They are spelled out beforehand, and the judges are given training. And just a side note, OOB doesn't mean "use Anything you find in the box", the "can't substitute parts" and "no major surgery" rules keep you from taking the Kit's Sprues and making your own missiles for under the wings, or for gluing sprue onto a wing to give it more chord or span, or gluing 18 carved sprue bits so that you can make a pilot.
As for paint (and aftermarket decals while we are at it),,,,,,,those have also always been covered in the IPMS OOB rules,,,,,,they are the "finish" on the model. That is why they are allowed. Aftermarket decals aren't considered to be "cheating", because you specifically are allowed to use decals or paints to put the entire finish on a model, which includes anything from a complete paint job, a combination of painting and kit decals, or painting and any decals you choose.
The category was never intended to be restrictive as to what your model looked like,,,,,it was just intended to be a "build it from a kit, only" type of category, without $147 worth of resin, etch and aftermarket underwing stores. (this has changed lately, you can now buy a kit for OOB building, and it comes with the $147 of "stuff" added right in that box)
It really is supposed to be a "you build your's, and I'll build mine, and we'll see who does it best" competition,,,,,,,,without all the constant "workarounds" that people come up with. It allows for rigging, for radio antennae, and for seatbelts, as long as they are within the OOB guidelines for adding those things.
OOB, as it was designed, was just a competition to see who could glue the best seam, who could fill it best without loosing details, who could paint without defects, and who could decal without silvering. (etc)
We could do the same exact thing with Evergreen sheets for each of the judging criteria, but, that lacks the visual appeal of having models on the tables.
Some people think we need to get rid of this category, I think it just needs to have some more wording added to it, and get it back to "just plastic" again. It could be so much fun, if people would just "open the box" "glue the model together" "putty and sand where needed" and "paint and decal it any way you want to"
2014 rules,,,,page 3 has OOB on the right,,,,,2015 rules will be slightly different, but, I don't know if OOB has any changes or not.
www.ipmsusa2014.com/2014_IPMS-USA_National_Contest_Rules.pdf
Rex