We use the manual as a small support machine for when we get busy. I will usually find some low quantity one color jobs to throw on the manual to lessen the load on the auto. Everything is faster on the auto as far as setups go, even one color jobs tend to be faster setups on the auto unless there is something strange going on. So a job like safety vests with one color logo is the only exception to the way we do things and will go on the manual always unless the quantity is over 100 due to only muddying up one pallet instead of all 12 on the auto. If the one color job is over 50 pieces it will go on the auto. But keep in mind, these examples only apply if we're busy and need to take some pressure off the auto. If we have a normal workload then pretty much everything goes on the auto.
I rarely sample or experiment on the manual either, but I have played around with silicone inks, HSA's and some DC stuff on the manual.