Mepstein, you have purchased some very fine gear. I am also a McIntosh fan. I have used a Hydra 8 with my McIntosh gear and didn't find that much of an improvement in sound quality. You most likely will get more of an improvement with some of the Shunyata higher level conditioners. I have not used Shunyata cables but have heard good things about them. I have used Wireworld cables with my McIntosh gear but have changed them out to Acoustic Zen Absolute interconnects and speaker cables along with AZ Gargantua II and Krakatoa power cables. For me the AZ cables are a perfect match with my McIntosh gear.
I have used a variety of power conditioners over the years. I now use a Synergistic Research conditioner for my front end and a Audience conditioner for my amps. I find for my front end (preamp, CDP, DAC & TT) I hear more of an improvement than with my Amps. I do have separate dedicated 20 amp circuits.
I think upgrading the cabling definitely makes an improvement. I never would have believed it unless I heard it with my own ears. You may want to try one cord and see how it sounds to you, but don't buy the least expensive cord from a given manufacturer. Just my opinion as I have not heard every cable and conditioner out there.
All the best.