The server should be changed to 128 tic. The other top DMs are 128 tic and for competitive players, having to play on 64 tic is not the same feel. You will increase the amount of players that use your servers.
I tried 128 tick awhile back. I couldn't get the rates just right for it to run smooth like I wanted. If you could tell me the rates that the other DM servers use and the servers runs smooth then I"ll gladly switch it over.
I went ahead and changed the server to 128 tick. I believe I have the rate settings correct, but I will be keeping an eye on the server to check performance.