From my experience since the past two years...
I used the TT via al fardan exchange...
besides that i used to do TT from QNB internet banking...
I do have some problem, but not with these two but my bank at origin..
fortunately al fardan they have good system..where you can get your money back...
But, always remember to have the copies of the transaction while doing this business ie:track/transaction no/receipt.
I've used to lost a lot of money...since the past two years..because USD is too weak compare to my country currency...