Using an external USB optical drive is an option, but from my perspective that is a compromise in an already expensive and supposedly "no-compromises" case. I already have a decent internal BR writer, sourcing an equivalent USB 3.0 or better drive is expensive (from what I recall).
It is a shame that ODDs seem to be either completely ignored or hidden away in the higher-end cases. I really like my R6 but I'd be happier for it to have a mesh-front and an ODD that isn't hidden behind a solid door (or to have that option at least). I know that the Define series is about being silent, but I don't see that Fractal - or indeed anyone else - offer a case that is the size of the R6 with a mesh front and an ODD. If there is such a case then it probably has room for 0.75 HDDs or something. I know not everyone wants to have space for 3.5" HDDs, but some do.