well less surfaces aid crema retention, and as you can see how it flows out you can also check to see if its evenly distributed when flowing. If its not, then your tamping may for instance be off centre, or if coming more from sides you might not be producing a good seal at sides of filter and coffee.... Overall, although its a handy thing to have its by no means nes.. In fact it can make you too pernickety and lose the spontineity ... certainly not worth 160 bucks plus del lol