It's not running on steam, which could mean a myriad little technical differences.

In many, if not most, cases, solar thermal plants do run on steam, the mineral oil or molten salt medium is solely for heat transfer.  Which is why one of the advantages of solar thermal over PV is that it can share a turbine with a natural gas fired plant.  Where there is sufficient insolation and empty space near natural gas fired plants, that should be a boon as natural gas prices rise and solar thermal equipment costs drop.

I'd say lots of extended piping (if the system is such) subject to daily heat expansion could potentially be high maintenance, as can be motors adjusting movable mirrors (if the system is such).

There are actually multiple configurations.  Solar troughs are highly expensive, but also highly efficient.  

Solarmundo fresnel collectors drive down the equipment cost by using flat plate glass collectors that are rotated on an axis.  There's a system of 6 of these that are concentrated on a single pipe.  This is inefficient, but much less expensive, because you don't have to produce curved glass panels.

Finally, the solar power tower concept uses a field of flat plates rotated to concentrate heat on a single focal point.  That means no piping, and superheating at the focal point.

My money is on the solarmundo fresnel collectors, because capital cost matters much more than efficiency when the fuel is free.

What I see is that solar thermal is a natural complement to natural gas fired plants where the insolation exists.  They can share a turbine, and that drive down the initial construction cost, plus the ability to switch over to natural gas in order to heat steam provides a natural backup.  In that case, the point is that the solar thermal installation allows for the conservation of natural gas, not replacing it.  
 

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