Re: If we went back to the old conditions. Who would dominate?
Hard to tell but from top players i would say Nole and Rafa would be worse, because their game is about movements, deffense, long rallies, on faster surfaces like old grass and faster HC, indoor carpet they would be worse.
Murray is hard to tell, with his style it depends if he adapt- with faster surfaces it would be easy for guys hit through him, but the truth is also it can help him redirect pace and absorb it, even his return on faster surfaces could be more dangerous, also Andy when on has good serve and volleys. So by Andy it is hard to tell.
By Roger, he has good serve, volleys could play great on carpet, faster HC, old grass, but big hitter would more easily outhit him like Berdych, Delpo, Soderling, Tsonga did it in last 2 years.
Delpo and Soderling would have more problems with faster surfaces, because they need time for their big groundstrokes, also their volleys are horrible so they can´t even help themselfes with net game so play from baseline with powerfull FH-BH is harder when you have less time, so they would be in worse situation than on today´s slower surfaces
Slower clay- it would just help Nole and Rafa for total domination on clay, nobody would came close to them, maybe Ferrer would be better there too with his stamina, consistency and return.