The mod is designed around making mining a process that requires thought and planning, rather than strip-mining at y12. Making minecarts useful and necessary is part of this. ore rebalance is highly recommended, as is boosters and better boats
The major change is that ore no longer stacks. Transporting large amounts of ore efficiently is going to involve designing a rail network with any necessary switches and logic to route chest carts to and from a smelting facility.
It's fun, trust me.
To make this possible without grinding for iron to make rails in the early game, the rails recipe has been changed to produce 64 instead of 16 per craft.
It's not implemented yet, but I'm working on improving smelting for large quantities of ore. I admit it's a bit tedious right now.