the advantage of using CZT ( CdZTe) compared to HPGe is that there is no need for extremely cooling down the detector. Slight cooling via Peltier elements is enough for CZT.
Thus no need for LN (liquid nitrogen) or cryo-pump.
However, there are some drawbacks:
a) energy resolution is quite bad, and
b) the appearance of escape peaks at ~23 & ~27keV below the photo peak; here is the demand of sophisticated deconvolution*) of the spectra.
With respect to NaI(Tl) the energy resolution is better.
For a comparison of the energy resolutions of HPGe, CZT and NaI(Tl) please have a look for example at Fig. 2 of:
Article Evaluation of scintillators and semiconductor detectors to i...
The following link may also be helpful for you:
Article Radiation Detector Materials: An Overview
*) but only, when there is a need for quantitative discrimination between closely adjoint x-ray or gamma lines