We've never had any major problems with our estrips. There were some real minor hickups at the start of the operations...
as japanac pointed out, it is extremely important to pinpoint exactly what do you want to achieve with estrips. in our environemnt estrips are mainly substitution for MTCD since assistant ATCO is sorting out the strategic separation. We are puting more and more info on the radars screen, but very carefuly, in order to take the burden off the exe.