I like the idea you can remove the drive cage. I can't stand cases with intakes whose air is immediately blocked by the drive cage. How effective is an intake that blows against a wall of metal?With these small cases, they need to just have one true 5.25 drive bay for optical and should adapt any other 5.25 bays to hold SSDs and HDDs. This way, the intake fans can blow freely across the motherboard. Most people don't need multiple optical drives any longer; especially not in a micro-atx case.
Also, there is no reason SSDs can't be mounted to the back of the motherboard trays. NZXT utilizes this design on a lot of their cases. You can even do this yourself without issue by just using some velcro if you have enough clearance between the motherboard tray and the case.
I think most people use their optical drives so infrequently, it makes sense to share a USB optical drive among all of your PCs.
I can see internal optical drives going by the way of the dinosaur; again, especially on a microATX build. Why are case designers still including so many 5.25 bays in general? More than one is hardly necessary for the average user. The only people who need multiple 5.25s are those with disk copying/duplication stations. Most of us aren't using our PCs for this purpose and if we are, we aren't doing it in a microATX package.