I sold my Cary SLP-05 after I borrowed a used BHK Signature Pre from a dealer. To me it sounded better stock than the modified Cary pre which was feeding a pair of Cary Founders edition amps. After a few weeks to get the sound imprinted in my mind, I started tube rolling and settled on a pair of NOS Telefunken tubes. I also replaced the fuse with a Synergistic Research Master fuse.
So to answer your question, in my opinion you didn’t make a mistake. Enjoy your new toy?