I don't own any T-series, but I can see the buttons starting to hurt after awhile. Some people just have more sensitive fingers tips than others. While others can carry a bowl filled with hot soup that just feels hot to them, it will burn me and I'll drop it unless I hold the bowl with something. What is a nice hot shower to some actually burns me, and my showers are too cold to them. I can feel roughness to some reader screens, whereas most others think I'm nuts and don't feel it at all.
So I can see it starting to hurt after awhile if they're made of hard plastic. Making them a soft rubbery material would have probably avoided it, only if they used a material that's a solid color throughout and not a surface-coated color that will wear off in time (like Logitech remotes for instance for me). Yes, I'm also picky enough that I would hate to see buttons with half worn-off coloring to them.
