Cross processing colour negative film in E6 chemistry is not something done often. The photo above looks great, but results are often disappointing. The effect of C41 film in E6 is the reverse of slide film in C41, you get lower contrast and saturation and more muted colours.
You will also have the orange mask to contend with and I would suggest that the photograph above probably had a fair bit of work done in scanning or post-production. I could be wrong, but I'd be surprised if the colours didn't need tweaking.
It is generally recommended to over expose by 1-2 stops, otherwise shots tend to be quite under exposed.
As for consistency, I think that depends on the variables you introduce. 'Traditional' E6 in C41 cross processing is always said to be very inconsistent, but personally I think it is fairly consistent for any given film. The big differences in results you see are mainly due to the different base colours you get and how a lab scans the film. In my experience the base colour will remain fairly consistent for each film, but how this is handled by a lab will vary widely.
I think the same thing would probably apply to C41 in E6. The same film, would probably behave similarly, especially if you scanned/printed it yourself, but changing films and labs, could lead to significant variation.