Precast concrete plunge pools are relatively new to the industry, lets dive in and compare:

Aquify Pools - Traditional Concrete or Precast Concrete Plunge pool?

The one advantage for precast conc plunge pools have compared to traditional concrete pools is speed.

Traditional concrete pool advantages over Precast Plunge pools are: you can get supply and install, no crane required, deeper pool is possible, custom shape size, will have an interior finish already applied, can have a pool larger than 6m x 3m and deeper than 1.5m.