Nine years ago when I moved here, I was told that Bangkok Bank had a contract with the US Social Security system, and that was the way to send my SS money to Thailand. I don't know if that was true, but things have changed a lot in the past few years with money transfers, wires etc. Personally, the thought of going to a new bank and filling out the massive amount of forms and paperwork needed to open 3-4 new bank accounts (mine, immigration, wifes), interent banking and mobile banking is mind-boggling and frankly, it's not worth the time or energy for me. Especially now that there is an easier way to get the 12 month statement. It's just one extra trip to the bank a year and a nice cup of coffee at the On On Hotel.
But I agree, if I started today, I would definitely go with the K-Bank and skip BBL.