The learning curve on padprinting is a big minus. I'm not sure I'd want to learn padprinting on tagless garment printing. That would probably be an exercise in frustration.
If you can get past that, the padprinter is significantly faster and requires no curing/catching/refolding as you can go box to box without even unbundling the shirts from dozen-stacks. It also takes up less space.
Padprinting gives you a less opaque print, which can be a bonus for tagless as you generally don't want heavy ink deposits, but you can't go into it expecting the same type of ink deposit as a silkscreen, it's not even close when padprinting on fabric.