As far as my choppy streaming ISO playback, it's not just one troublesome ISO - it's all my ISOs. And they are only troublesome because they won't stream smoothly. As I said, it may play smoother when I drop a spare drive into the unit, but as far as streaming goes, it's way too choppy even with my gigabit switch. It might have to do with Windows using the drive for other tasks at the same time, I don't know. I'm not multitasking when playing ISOs but there are always tons of processes running in Windows, so maybe it's just too much for the drive to play smoothly when Windows decides to access it for something else while playing. I really don't know.
And the menu is not simply to play the movie itself - many (if not most) Blu-Ray discs contain extras - sometimes tons of them, which I want to view. That's the whole point of ISO playback - to play the menus which will enable easy access to the extras (deleted scenes, documentaries, etc) as well as the feature itself, all in full quality. When playing a 3D ISO you have to do direct-play with no menu option, but if you want to see the extras after, which are usually in 2D, you can just restart the ISO with the 1.0 menu and you have access to the extras.
Also, makeMKV won't do any good for those of us who want to watch 3D ISOs, since you can't make a 1080p frame-packed mkv. If you want full 1080p/24 playback at full Blu-Ray quality, you need to be able to play the ISOs (or BDMV folders). So ISO playback is important for alot of people. It's not just about playing the movie. It's about playing the whole disc.