After spending just under a year in Chiang Mai, I highly recommend the capital instead. BKK is slightly pricier, but the magnitude of the city is so much more satisfying than the oversized suburb that is CM. Yes, the mountains surround CM, but it is more a getaway destination than an ideal startup/freelancer hub as far as I am concerned. You will also find the infrastructure, including access to Cupertino technology — more advanced in the southern capital metropolis. BKK is the wonderful heart of The Kingdom for me.