In which case, you are doing something wrong, as I had my sorting system dealing with a quarry running at max speed with no issues.
Had? When? Because the speed of quarries has been upped. If you have 2 redstone energy cells at max power they really fly. And look at Direwolf20's new system. He has multiple sorting machines on his input chest too.
The key thing is the first sorting machine should pull out stacks, not items.
This doesn't make sense at all. The rate the quarry comes in vs the single sorting speed cycle rate is the problem. I watch it frantically dump out the incoming cobble (you'll see like 4 at a time come in, then they vanish, and more stuff appears before it keeps cycling.
I think you're also misunderstanding the problem; the problem is at max power the quarry can sometimes overwhelm my recycler capacity in some cases. (In particular when random distributions of items into the recycler farm mean that only one recycler can process gravel or marble, for example). I'd love a way to safely and effectively void pipe that, but such a bridge is actually pretty awkward without a really powerful engine hooked up to a wood pipe.
The sorting machine will always prioritise items in it's filter/sorting area (starting top left) over unsorted items, so if you have cobble assigned to a specific colour in the left most column, this will always get processed first over any other item.
My recycler line is the rightmost line and is reserved for only those things. Special color, not default. Because I noticed the prioritization behavior immediately.
By the way, effing quartz crystals. I know Soren is a cool guy and all but man are these things a pain.