walking on smooth edge

My last post was about carpet meets tiles over a walkway/doorway
You blokes have said to use angle and a smooth edge. Sounds good and its the finish im after, but...

Ive just walked barefoot round the edge of the carpet already in my house. The smoothedge creaks a bit---> bear in mind its a slab floor so i guess masonry nails dont work that great and the smoothedge has movement
But also the pins in the smooth edge stick into my feet through the carpet quite easily.

is all this unavoidable if i want the neater finish and not use a T peice overlay?

thanks

any way to get the smoothedge to stay firmer than using masonry nails? screws and plugs perhaps?