I agree with your conclusion. Some remarks though.

I don't think the voting process itself gets sped up a lot just because you tap a screen instead of crossing a field.

The tamper-proofness is certainly attractive, however what we have on the market today is so far from that goal that one has to consider it less secure than paper by several orders of magnitude.

Slighty oftopic: I just found out how embarissing little I knew about accessibility processes in elections. Therefore thank you for mentioning that ;)