I've had the Borgeson shaft in my YJ for about a year now. Noticeably less slop and vibration in my steering, but then again my old shaft was toast. Joints were bad and the slip joint was frooooozen solid.
It's a really nice heavy piece of steel. It'll definitely outlast my Jeep. Rubber boot over the slip joint. Splines were really tight on my column and Durango box. Really nice fit. The slip joint is kinda' hard to get moving, but this is only really a problem during installation. It'll move just fine when you smash into a tree.
With steering and brakes, you really can't skimp, IMO. Safety first.