[Drako]

Do you recommend using this type of RATs, or is it better to use Metasploit / Meterpreter?

The best free RAT right now is probably going to be Quasar. All of the cracked ones at the moment are infected. And all of the old ones are outdated. And by the way, Metasploit and Meterpreter are vulnerability scanners, not RATs.