Also, in addition to posts above from nbp and scout24,
June, 2015 is when I discovered Vinh, when I realized that my favorite US supplier would not be offering the Noctigon Meteor M43vn XP-L.
Chronologically, first reason why I went with Vinh was/is his providing on-time wide variety of offerings.
2. Supply and support stateside, no months long slow boat to/from other corners of the globe.
3. He does mods that I can't do: Boost and choice of alternative emitters, etc, etc.
4. Prompt, friendly attention to seldom seen minor hiccups.
5. Prompt, friendly response via email.
6. Heartfelt, personable, spiritual presence on the forum.
And last, but eventually most, 7. After buying 26 lights from Vinh in the past four and a half years, and after lots of friendly, helpful and personable emails and one friendly, brief instant answer phone call, I consider him to be my very close to primary spiritual asset/spiritual connection in this phase of my life on the sometimes hostile surface of this earth, painfully impacted by evil people.