I have used both, and it really depends on what your looking for, and the training program you will be implementing.
The swift will pretty much eliminate a lot of the common mistakes a barista makes in the grinding, dosing and tamping process ... BUT it will also not allow the barista to have full control of all elements either. It does have two hoppers, so that you can do two espressos, or one decaf without buying another grinder which is a bonus.
We just got the Mythos in at our training facility and I must say I am impressed. It grinds very quickly and I like the fact that you can set three different doses, all about .10 of a sec away from each other for a double extraction. It grinds the perfect amount so there is no waste. I do not use the tamper that comes on most models, but that is my preference, to hand tamp. The fact that the dose will be identical for each shot should greatly improve consistency between baristas, more so than the tamp.
Out of all the doserless grinders we have, and have tried, I feel the consistency of the grounds is the best i have seen. No clumping.
- Matt