Befpore you decide not to lock cheack your holiday insruance policy. Most policies will not cover goods lost if the suit case did not start out locked.
I have used the TSA locks and have had cases opened and then relocked without any issues. However, it does appear that if the lable on a suitcase is not filled in properly then they may be more likey to open it. On two seperate occasions I have brought a suitcase and then filled in the name and address quickly, once with bad writting and once I put the name and post code on only as I was in a hurry, and forgot to complete it, both of those were opened.
I have used the TSA locks and have had cases opened and then relocked without any issues. However, it does appear that if the lable on a suitcase is not filled in properly then they may be more likey to open it. On two seperate occasions I have brought a suitcase and then filled in the name and address quickly, once with bad writting and once I put the name and post code on only as I was in a hurry, and forgot to complete it, both of those were opened.