I have some of the Gillette yellow blades as a free sample with my razor and have a mind to try them in the 34C HD next. Currently on a Tweet but don't see much difference between that and the Derby but only my first day of using it. Derby blades do seem mild and takes a few goes over coarser growth.
Do have Wilkington Sword black/white packaging as well as some Lord and Personas (thanks to Andy) to try but wondered where these all fit on a general scale of 1 to 10 from least to most sharp and also how forgiving too if possible?