The Lord Flash

I have had a Blademaster BRC 2005 for about 4 years now and think i do a pretty good job for my local club in sharpening their skates. Not such a huge sport in the UK but i am now keen to be able to offer FBV to everyone and maybe even custom radius (combinations actually- i already have a Mk V system) anyone know of the differences/preferences between the Blademaster and Blackstone systems? My existing machine doesn't have a magnetic table top so i may have to have it re-done or just buy a new one. The bigger "spinner" wheels on the Blademaster look/seem appealing but i genuinely have no knowledge or experience of either system. As and aside i have always wondered how if yo start with a blade that has eneven edges how the touch/v-maks work? If say the lower edge is high it will contact the wheel first giving you indications that you do not have the wheel and blade centered where as you may well do it's simply the edge offset. Adjusting the blabe up or down here would encourage you to put the centre of the ROH away from the middle of the blade? A flat grind (crossgrind) with the little dot witness marks in the centre of the steel is obviously spot on but you don't want to cross grind each time. Also i have read that contouring should be done with the radius of hollow set and the blade and wheel held in the normal horizontal plane ( i believe it was on the No-icing .com site) is this really feasible? They also mention a Z grind or something which i had never heard of... Thanks for any comments.. TLF