Before March 1 2014 the travelers check was the best way for me to bring money, good rate vs $100 cash, now it is a big mistake to have travelers checks.
I went to exchange money at the bank, exchange rate was posted @ 32.35 but I end up with 30.08 ???  ($1000.00 US dollar TC).  Thats 150 baht per travelers check!

I lost 1500 baht to the new exchange fees, its much cheaper to use your home countries ATM and withdraw 20,000 baht at 1 shot and get charged 150 baht, last month I exchanged money at 280 baht banks exchange fee.

The text below is from from trip advisor (edited):
Travelers checks

If you prefer the security offered by travelers check, then take them in your home currency if available. i.e. If you are from Britain, do not get USD check or you will lose money on that exchange before you have even started. In some cases there is a fee to buy travelers check.

  • When you exchange travelers check in Thailand as of March 1, 2014 there is a 153 baht fee per check (up from the previous 33 baht).
  • To minimize this 153 baht fee it is wise to get your check in larger denominations (i.e. fewer exchanges).
  • T/Cs actually get a marginally better exchange rate than cash, which will help offset part of the fee. (dont believe this)
  • When cashing T/Cs you will be required to present your ID (i.e. Passport).
  • T/Cs provide improved security for you, as they can be replaced if lost/stolen.
  • Only American Express checks or Visa TCs are accepted. Do NOT bring other kinds of check such as Thomas Cook.
 
This note is from the webmaster of sananwan palace.