Based on the recommendations here, I have decided to send my two set of regulators to Profix prior to my Christmas trip. I'm happy to report that like many others, Joshua is indeed highly recommended. He is a certified technician for most brands and yes, his work station is impressive.
Quality of work is excellent. Usually I don't really bother about regulators but this time I actually felt the difference in breathing effort. It's more seamless now and I really like it. Also, my regulators actually looks quite good when he returned them. He probably did some cleaning up.
Look no further, Joshua is the man!