If my lbs didn't have the required support equipment needed to take care of Di2, I would be really hesitant to buy it as well. In the early days, I helped them debug a setup because it was the first time they had to do it and Shimano's software didn't work on their macs. My understanding is they have done this many times since, but probably only a couple of times a year. I think they had to borrow some equipment from Shimano that time because the problem was in some weird part. Not sure if that has changed.