The Wyskstra line is interesting, but I think by itself it isn't a sufficient response. It can be too easily reversed onto the Theist - what relevant epistemic access does he possibly have to affirm God is morally perfect, as opposed to anything else (how'd you tell, perhaps, between morally perfect and just 'very good indeed?') It isn't an insurmountable objection, but I think it shows Wysktra's line runs into very similar difficulties that people have thrown at religious experience. Wysktra's argument implies concession (even if only for the sake of the argument) that the EPoE appears sound - that, commonly, the world seems to suggest that Theism is implausible, due to the presense of evil, but, according to Wysktra, with proper realization of our limitations to witness this, we can only deem this argument as inscruatable. To overcome this and affirm Theism, you need to find some sort of 'special sort' of experience which is not subject to Wysktra's criticism. But I don't see how this can arise - one perhaps has even greater grounds for fielding (ironically) Humean objections to the idea of Theism borne out of religious experience or the like, and I don't see why one couldn't affirm other 'special sorts' of experience (moral outrage, emotional despair) to try and 'cancel this out.' In other words, if Wysktra's argument carries, I think Theists would be epistemically obliged to renounce their Theism through lacking the very sort of epistemic access necessary to make a judgement of such scope.
However, I don't really like this sort of 'you too' argument, although it works well in debate - it might give one's opponent a reason for dispensing with the argument, but it doesn't actually show it to be mistaken. But I think it is. The main reason is that evil, particularly the most heinous, gratuitous sort, doesn't really strike anyone as 'inscrutable.' Some things are so bad that it doesn't only seem factually absurd but morally reprehensible to consider the possibility that these can be any sense 'ultimately' a good thing, which is precisely what a theodicy must show. Of course, that is no reason to discount a possible explanation on the back of this, but I think it shows that it is pretty implausible to consider these judgements inscrutable. One could apply Wysktra's line of argument to any sort of axiological judgement, and that seems absurd. Further, in some cases, if the supposed morally sufficient reason is suitably remote, it mightn't even be good at all. Even if it could be shown with some perfect knowledge analysis that the Asian Tsunami or the Second World War was ultimately good for the world, I don't think we'd change our judgement that these were, in fact, bad things.
Rowe lets Wyskstra off pretty lightly in his response to him, though, so maybe I've missed something he's picked up on.