Sports cats

[S6 Devil]

Has anyone an opinion on these? They don't look like the normal cheap ebay rubbish. I'm decatted at the moment but wonder if these may be a good idea.
http://www.ebay.co.uk/itm/161612482838?_trksid=p20...

[S6 Devil]

Not sure what standard are but TVR parts sports cats are 200 cell http://tvr-parts.com/tvr-parts/part-details/tvr-s0...

[S6 Devil]

Dom mentioned preferring cats on his rebuilds. I have decats and a chip but it still doesn't get through MOTs. I'll probably stick with decats but like to keep my options open.