I picked up a ST-22 complete .22LR upper with the SAR rail and I'm impressed with it so far. Looks good, feels good and seems light. The machining on them is excellent. There is a small tab just below the upper rail that aligns the rail with the upper. Seems to be perfectly aligned, nice touch. It's no better than DD or LaRue, it's no worse either IMO. Only thing I'm not happy with is the QD swivels, they do not have anti-rotation limiters so the QD can spin freely. Other than that, it's a nice rail.
ETA - I have rails from all three, DD/LaRue/Spikes so I am basing my observations on experience with them all.
Full disclosure - I am an Engineering Supervisor at Trijicon, Inc.
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