anyone know how the amount of draws differs from when DRS is used compared to when it isn't ?

A lot more LBW decisions are given these days by umpires since DRS has been in operation

Don't know the answers but shouldn't take too long to plough through the matches on cricinfo to work it out. Would be interesting to know but you'd have to balance with a bit of scepticism given the locations where DRS tends not to be used (in the sub continent as India never use and Sri Lanka etc can't get the funding for some of the less fashionable series). My thinking is that DRS has simply influenced a trend of more positive umpiring decisions for LBWs whether or not DRS is actually used in a given match but I'll stand corrected if the stats suggest a pattern.