Tripple angle cut on the head - A bad idea

[rossmac]

Im taking my head to have tripple angle cuts done tomororrow & i was wondering what peoples thoughts are,Apperently it helps speed up the air/exhaust going through the port,if this is the case is it a good idea to get all 16 valves done or only have 8 done?Im just thinking that it may be a bad idea if i get the exhaust done too & it makes the exhaust escape too quickly so the pressure will drop?Any advise on this topic would be appreciatedthanks