They both are good tools but in different ways. PCMtuner has a lot of obd modules for Asian etc, but cannot do any BDM Jtag work or Agri and plant like KT200.
KT200 has more new protocols and with the possibility of reading TCUs than pcm. But it does not have tuner account and tuning service for tuners.
pcm tuner has better technical support and no annual fee. kt200 uses an annual subscription model for updates.
Each tool has its own capabilities, not all tools can do read/write perfectly. Buy both, PCMtuner has very good coverage but can only do certain bench jobs (edc17/med17/mev17) and limited boot. It depends on your needs, no one tool is ever enough. The 2 machines are complemented. The more tools, the more work you can perform.