Hot gas defrost

Hello friends from RE, how have all you been? Hope all you are fine!
Sirs, I'm new in comercial refrigeration system, since 1984 I'm working with this but my skills is more in medium and high capacity liquid chiller, now I'm arested and like to work just near my home and this is the way.
Like to hear about hot gas defrost system, because one supermarket that I have visited, talking to a maintenance guy, he said to me that has a lot of problem with the small equipment that use R404a and Hot Gas Defrost, in special with compressor fails. Like to hear yours field experience about this. Any comments will be appreciated.
Thank you in advance for your attention.

Sorry Sirs about my poor English: "I'm retired" not "arrested" :D

brztech,
Maybe you are semi-retired:D
Your question is very open on hot gas defrost.
To me does not matter which refrigerant you are using, as if set up correctly should be no problem.
There are many ways to do it & it is highest priority to protect compressor with suction slop pot.
I think in this situation more information required at local supermarket to comment, we then may be able to help more.