It says on cz's site the shadow comes from a different mould with a few ergonomic changes. Is this the only sp-01 using this new mould or are all new sp-01's using the same frame now? I can't see any difference in the photos. the only difference i see in any of the frames, (sp-01, tactical, and shadow) is the number of slot's on the light rail. Some have 2 slots and others have 3. If there is a grip difference is it significant? Thanks