It could easily be seamless, assuming the um,pire behind the plate (who has to be there, since robot umps only do balls and strikes and NOT plays at the plate) would still be the one relaying the call to the viewers. He just does't have to perform the impossible taks of deciding whether or not a ball traveling at close to 100mph from maybe 50-55 feet away touched any part of an invisible box. Instead, he gets feedback from an automated system. Maybe if MLB had fewer pitchers capable of throwing 100mph, like they used to, this job would be easier. But they don't and it isn't...