Castle should be quicker at solving problems like that as they are writing their own OS whereas MD will have to ask ROL to fix things.
Of course if you want Select you've only got 1 choice ATM.
Now the generation 4 machines are available, what's in store for generation 5? Castle would seem to have the lead here, although they're relying on a chip with in built everything. If a similar faster chip appears they're fine.