performance, as in CPU performance?  For sure you're gonna get much greater performance using just messages.  

It's also MUCH simpler to sequence with a [metro] and messages, and very easy to do interesting things to a sequence. 

compare that to something like this, in the link claude just shared:

https://archive.bleu255.com/0xA/files/2016/04/010_shuffle.png

what a mess!  

I see what you mean about having a single master clock, but why not just have a single master clock that's based on [metro] and a counter?  You can use that clock to trigger sub-clocks to whatever resolution you like, right down to subsample accuracy.