The image shift problem is due to the inward curve of the center channel, and is the SLA center's main flaw. Because of the inward curve, though it allows a little more distance for driver to driver integration, it shifts the center image in front of the speaker, so move to the right, and the image from the speaker moves left, and vice versa. IMO, an SLA center should be curved outward, so that the image is behind it, and shifts less with listener placement. But then you give up almost a foot of integration distance, so goes the compromise of array design......
For a low dollar, WAF friendly shape, it is very good, but as you can see, like all arrays, it requires EQ in the upper octaves, just make sure you have plenty of headroom in the AVR for it, to avoid clipping the amp. The curved shape will lose more in the HF region simply due to the curve, and without EQ, would not match the mains sound, even though all three speakers use the same drivers.
Pics of the whole setup?