Im just looking at all options to improve steering (not including the astro/jeep shafts). Apparently there are other companies that make shafts, although somewhat expensive. Has anyone used something like this

 

If you're having steering slop, and have replaced the rag joint and adjusted the steering box itself, plus have replaced all the tie rod ends, both inners and both outers, with new aftermarket adjuster sleeves, and have replaced the idler arm and the center drag link, then the Astro / Jeep shafts will solve anything remaining.
I did the Jeep shaft to my '87 S-10 to clear my V8 swap. The improvement was barely noticeable, and may have been the placebo effect, but it gave more header clearance.