Baffled by wide angle zoom choices

Ok I have studied reviews on Dyxum, Amazon, Photozone, Kurt Munger, etc., but still, every wide zoom apart from the CZ which is too pricey for my pocket, seems flawed.

Between sigma 10-24, 12-24, Tamron 11-18, the new Tokina offering, which are folks happiest with? And do the Sigmas need re-chipping to work with SLTs?