Han I agree except that there IS competition, STEM is also trying to do what sounds an awful lot like ACTC's protocol.
Nevertheless ACTC is ahead in the race, and there is plenty of room for 2 technologies, the same way there are dozens of hip implants available, and many brands of pacemakers, etc. If ACTC gets good results and gets FDA approval first, doctors will think of ACTC first. Just as ISRG has a huge advantage in robotic surgery technology by being the first, ACTC could have a huge advantage if it is first to market.