When you are brewing a beer that calls for a multi-step mash you get a more accurate to the desired style end-result by using that technique. If you substitute an infusion mash you get a different beer. Note I do not say either is better - thats a matter of taste. However you do NOT get the beer that the recipe designer intended if you change the mash.
Re your other post on electrics, sorry but I must completely disagree. if you are are a qualified electrical engineer you can make your own decisions and fully understand the risks you are running. If not, you should ask one. This is not an area where a bit of internet research can make you an expert. If you are using an stc-1000 to drive your elements you should use a Solid State Relay in between to manage the multiple on/off cycles per second the STC-1000 will command. Fail to do this and your kit will melt down from the heat generation. Even with an SSR you need a really big heatsink to draw off the excess heat. You should also use an RCD as a matter of course to protect you from short circuits because brew systems use lots of stainless steel, copper and water all of which is highly conductive. You have one life and brewing is not as important as life. Of course it is about second most important ;-) Sorry to lecture but there is no margin for error on this stuff.
Re your other post on electrics, sorry but I must completely disagree. if you are are a qualified electrical engineer you can make your own decisions and fully understand the risks you are running. If not, you should ask one. This is not an area where a bit of internet research can make you an expert. If you are using an stc-1000 to drive your elements you should use a Solid State Relay in between to manage the multiple on/off cycles per second the STC-1000 will command. Fail to do this and your kit will melt down from the heat generation. Even with an SSR you need a really big heatsink to draw off the excess heat. You should also use an RCD as a matter of course to protect you from short circuits because brew systems use lots of stainless steel, copper and water all of which is highly conductive. You have one life and brewing is not as important as life. Of course it is about second most important ;-) Sorry to lecture but there is no margin for error on this stuff.