The second you introduce alternative type media, there is going to be more staff to work the gates. Phones and smart watches are convenient but they are also only on one person. I have seen it hundreds of times where the patriarch of the family has all the passes for his family and insists on scanning people through individually. Granted most of my work is at concerts and sporting events but it holds up the lines. In the case a family will have 2 smart phones and 2 bands for the kids, he bands are ready to go, no issue. The phone, usually locked, will be unlocked in preparation for the gate. If the person in front doesnt finish quickly the phone may lock again, media needs to be accessed again. It may sound petty but this is what I do for a living. I help my clients get people into their events and one thing that is consistent across the board is that only half of the people using phones as their entry method can go as fast as a traditional media. The RFID points for the gates are a whole other story. The contact point on the phone and the reader is going to be completely foreign to a lot of people because when you use it at the store it is a little more forgiving.
You may just say, "thats not true! I can' use my phone and I'm super duper smart" I can only say that for 8 years I have been watching the progression of ticket media and this is not faster, not by a long shot.