However, the new mining system has more benefits compared to the old mining system. I'll list it out the pros and cons for it according to my experience.
New Mining System
Pros :
Can mine specific minerals, such as Coal.
Steady profit.
Has a range of pickaxes with different durability.
Handy for Crafting
There's level system to gain access to specific pickaxe and minerals

Cons:
Takes time to level up.
Have to spend more money to level up.
Bats and falling rocks will occur if you remain idle.
Rock Hoggers (Because of the 5 second *Ownership*)

Old Mining System
Pros :
Have a chance of hitting more than one rock at the same spot.
No mobs appearing and attacking.
Fixed price for pickaxe.
No level system.

Cons :
Minerals mined is based on chance (With coal having a low chance)
Profit can increase or decrease depending on chance (Again...)
Can't mine specific minerals.
Can take a long time getting specific minerals for crafting