I'd say if we set up a blind test, and can he pick the "factory" OH vs the "raw" OH, at least 4 out of 5 times, then I'd agree there is a difference. I kind of don't think that would happen though ......
I've purchased OH and ML IR packs based upon the factory 'sample' IR's in the unit and darn if they don't sound identical to me....
Then again, we are talking guitar players, and guitar players can always hear "differences" in things that realistically don't make any difference. I mean lets face it, how many hundreds of times have we heard someone on the forum say "_____ amp sounded better before the update" and then Cliff comes in and says that absolutely nothing changed on that amp model LOL