I think he just meant the word titanium sounds cooler than stainless steel. Can't say as far as the gas block but for the gas tube I'd just stick with SS, it works.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek