I believe you veteran guitarists when you say tuning machines are rarely the culprit for tuning problems. Still, I've got mod fever and am gonna upgrade my Epi to higher quality Klusons. I don't have tuning issues but my D-string peg is a tad wobbly by comparison to the others. My guitar is fitted with press fit bushings but am inclined to go with hex head style threaded bushings. Do you think one style is better than the other? I realize it may require reaming to fit hex head bushings (will have local luthier install).