i was reading on the web site that conducts all the 4x4 wich competitions and punch trials (forgot the name) and they have a list of approved tyres for competion use, mainly to cut out the damage done by serious agressive tread patterns. IIRC the diamond pattern was under review to be made illegal for their competition use. not sure as to whether they have implemented it or not but they did compile a list of approved tyres.i didn't include the simex as it is a very agressive tread pattern of the bfg where as the recip tread is totally different. the recip is slightly more noiser due to the edge tread pattern but was interested to hear peoples opinion of the two, mainly because i will be needing new tyres at some point so still unsure which way to go in regards to patterns. Dont want to use simex as they are too agressive for what i want from a tyre