Metal ends and absolutely flat outer ends (I use my angle grinder) made my Jagwires absolutely fine.
I use gear cable inners in brake outers on my mtbs – never had one break in 10 years and the reduced friction means more power goes to braking. Also means you don’t need both a spare brake and a spare gear inner in your pack.
On road bikes you are stuck with brake innners though. I’ve found there can be a big difference in performance and feel between different levers (Sora and Tiagra – 2 different generations of). Latest version Tiagra gives better feel and pad clearance without sacrificing power over previous generation using the same calipers and cables.