You can't really use any carbide tooling, the tool post/cross slide/compound just isn't rigid enough.
Unless you're machining one of the "space age metals" like Invar, Kovar, Nitraloy, Hasteloy or something similar, carbide is not essential. High content cobalt/HSS, Stellite or Tantalum-tungsten will do the job nicely and without the brittleness of carbide on nearly any high-carbon steel, stainless or even titanium.
As far as extreme precision lathes go, there's only one that I know of that beats a Hardinge HLV toolroom lathe and that's a Monarch EE. NASA bought one back in the late 1950s and sent it back to Monarch in about 2010 for rebuild and electronics upgrade. Monarch sells rebuilds of the EE model for about $77,000; new run about $120,000.
With regard to ease of single-pointing threads, nothing beats a Hardinge HLV.
While I would never consider parting with my Bridgeport mill or WEBB engine lathe, as I know the complete history of both, and neither have more than 20,000 hours on them. I also know all the machinists who worked on them.
Had I not been fortunate enough to score the commercial lathe and mill, I'd probably be looking at the same equipment that Brad purchased. Precision Mathews may not be the equal to old "American Iron" (before it got old), but in the not so distant past I was tasked with sourcing machinery for a new machine shop being created by a major motion picture effects company and according to what I learned in my research, PM makes consumer level machinery that has and does often cross over into the commercial sector; it's good stuff.