If you transact with STK tokens: just as in the above example, the user pays no fees.
In summary, we have significantly improved the architecture to the benefit of both members and for STACK. It costs about 34.8 % less in gas for a member to transact using a Multi-token payment channel than with a traditional single-token channel.
34.8% is a significant cost reduction in fees. Less fees can help increasing instant payments in the point of sale. However this post doesn't help to understand the technology that causes this reduction. Please share more info that will make understand it.
Not only there is a reduction in cost but also the speed of the transactions happen instanly because of the state channels that are developed and they can do transactions offline. And when the channel is closed then the txs are going to be processed online in the blockchain.