I think I recall someone or some reviewer somewhere stating that the
Hardin has a plastic secondary holder/spider that is not adjustable--is
this correct--I may be mistaken, but it's worth looking into. The Orion
has a steel spider.

I have an OPT Star Hunter 10, same thing as the Hardin scope and from the same
company that made the original XT-10, this is essentially an improved version
of the original XT-10. Great scope IMHO.

These scopes have a nice 4 vane steel spider assembly that is fully adjustable.
The secondary mirror holder is plastic. The difference between the Orion/Synta
scopes that I have seen and the GSO/Hardin/OPT is that the GSO scope enclose
and capture the secondary whereas the Synta secondary mirror is apparently just
glued in place.

Both work, but personally I prefer the fully captured design. I have seen
several 1.25 inch refractor/SCT diagonals that had the mirror glued on
improperly causing bad collimation. A poorly attached mirror that comes off
can be a real disaster.

The captured design, at least in some of the earlier 10 inch GSO models,
sometimes pinched the secondary and caused astigmatism. Mine had this problem
but once I discovered it and corrected it, the optics have turned out to be
quite amazing..

Collimation:

It should be relatively easy with the Hardin scope and one set it should only
require minor tweaks. Last year mine went on a 10 day, 2000 mile trip in a
motor home, in and out and setup every night, bouncing around and accidently
banged a few times. The collimation never needed to be touched.

Personally I recommend a good quality laser collimator and a collimation cap.
I first set the rotation of the secondary with collimation cap or cheshire and
then use the collimator to set the secondary tilt and Nils Olof Carlin's
"Barlowed Laser" technique to set the primary tilt.

The focuser should be square already, the new Hardin scopes have a nice looking
(in the photos anyway) Crayford focuser.

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The primary advantage of the laser collimator is that one can use it anytime,
day or night. Cheshires are daytime only, star testing requires a nicely
cooled scope and good conditions.

I also recommend spending a few dollars extra and buying a premium laser
collimator like a Howie Glatter. (www.collimator.com) Normally I buy on price
but I wanted a good one so I spent a few dollars extra and bought one of
Howie's master pieces. I have had it about 5 years, still in perfect
collimation,it is made to close tolerances and is still on the same battery.

In my view, having a good tool like a Howie Glatter is something I will have
and use no matter what scopes I might own, its an investment, quality alignment
tools are a big help in getting accurate collimation. Howie machines these
from solid aluminum to tight tolerances and they are nice to look at...

It is my understanding the asian collimators are sometimes out of collimation
when they arrive and can be somewhat sloppy in the draw tube.

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Anyway, I think you have made a wise choice, I really like my GSO 10 incher,
lots of bang for the buck and for some of us, the ideal tool.

A DOB is like a bicycle, it won't do anything for you that you cannot do for
yourself, but those things you cannot do, it does a marvelously.

Best wishes, clear skies

jon isaacs