Mediocre reviews online.
As with any rebuilding service you should be aware of critical details to tell you if they cut corners or not.
Did they use new expansion plugs? Can you see a brand new head gasket poking out? Pull the valve covers, has the head been clean at a shop? Are valve springs and stems new or very very clean? Are the push rods new? Its usually good to replace a cam on a rebuild, which means new push rods, new valves stems, new springs and rockers. Is there a new gasket on the valve cover? Can you see new rtv at the water neck, water pump, and timing chain cover?
Also on the receipt always ask for the actual man hours it took, and a parts breakdown of cost. Compare the parts cost to retail. They can not legally mark up without justifying a service. They can not hide these prices from you either. Compare the receipt to what you see on the engine. If it lists new springs or a "complete head rebuild" but the valve springs are obviously the old ones....
My .02 exp earned the hard way. Hope its helpful.