They both (SR Orange and Green) have apps and web pages. You can check the rates at any of the locations. The difference between SR Orange and Green is usually not that wide that it would make a significant difference to most people, but sure, there's a small difference, maybe 15 satang per $100 USD when comparing SR Orange at BTS Asoke (very convenient and busy location) vs SR Green HQ rates. A more reasonable comparison would be HQ rates vs HQ rates, which narrows the difference to 2 satang per USD$100. 1 satang = 1/100th 1THB. How many people here would go out of their way for 2 or even 15 satang per $100?

The rates at any of the SR Orange or Green are heads and tails better than the rip off places you see elsewhere around town or at the airport. And a fee free debit card with ATM rebates is of course better than any of them because you don't have to go hunting or traveling for anything, just use the nearest ATM.

Another FT favorite is Vasu Exchange, located under the BTS Nana station on Sukhumvit very close to the Hyatt Regency Sukhumvit They have a website with their rates. You can find it on google maps including a link to their rates.

-David