music hall dac25.2-rca or xlr?

Just got a new music hall dac25.2 which sounds great. I had to order cables so they loaned me some rca cables that sound pretty good, but now i read that xlr cables bypass the tube and rca cables utilize the tube.
Does anyone have experience with either or both rca and xlr? What is your preference?
It seems like using the tube is the whole idea. Any Input?
Thanks
Roger