I have used home made Tangential Turning tools with 1/8, and 5/16 HSS toolbits. The commercial Diamond turning tools use 1/4 toolbits. They all work well, in my experience, as long as they are kept sharp.
There have been at least two designs published to use 1/8 HSS bits. My 5/16 one was just a magnified version.
For turning or facing, I use almost nothing else. Will remove metal at almost unbelieveably small cuts.
Sharpening is dead simple, only one face to grind! The holder produces the clearance angles.
The only use of carbide tips is now roughing (100 degree corners of CCMT0604 ) boring, (80 degree corner of CCMT 0604 ) or radius turning (rare ) with 55 degree carbide tip. I suppose that atrainguler, 60 degree tip, or a 55 degree tip can be used for screwcutting. But on the rare occasions, for external Metric threads, I have used a metric thread cutting tip.
Tangential tools get my vote! (Easy to grind HSS so not prone to chipping, and inexpensive )
Howard.