They absolutely make a difference!
I have tried four options and can hear the difference between all four when used as a transport feeding my Bel Canto E1x integrated amp/dac -
Bel Canto CD-3T CD transport (best sounding)
Marantz SA-K1 Ruby SACD player (next best)
Oppo BDP 103 BluRay player
Yamaha CD-S1000 SACD player