On Sat, 24 Apr 2010 20:33:12 -0700 (PDT), Searcher7
wrote:

I have a mini-lathe, but even for those with the larger machines I was
looking for opinions on whether or not the "Adjust Tru" feature on
something like the Bison is really worth the money.

Is any gain is speed or possible accuracy really worth the cost that
these go for?

That's up to each to decide for himself.

I have a Buck Adjust-Tru that I got used 20 years ago. The D1-4
backplate I had to buy cost more than the chuck. That investment has
definitely been a good one for me since that chuck is what's on my
lathe 95% of the time. I'm a hobby machinist, production is not an
issue but convenience is at times.

Work can be centered accurately in a 4-jaw but it takes a couple of
minutes of screwing around.

The adjust-tru isn't accurate for all diameters unless adjusted, but
it's more accurate than my other 3-jaws and it's well under a thou for
1" dia stock -- or such other dia as I may find it worth the bother to
tweak. That's close enough for my needs most days. For closer, 4-jaw
is actually more convenient.