As a hobbist that has repaired and made tanks for others. I have spoken with and even met people in the industries that design framless tanks. I notice two things about those tanks you have shown. First, would be the glass it seems to be of a blue glass nature, in other words it has a blue tint to it,most tanks are made with this type of glass. However if your going frameless see if they make them out of a white/cystal glass. You will thank me later, it costs more but clearity of the tank is worth it. Secondly, I would like to have seen, glass strips attached to the bottom inside of the tank, and in the corners. There is alot of pressure on the sides and bottom of a tank once they are filled with gravel water and decore. They guys that make custom tanks will tell you there is less cahnce of leaking with these installed. It basicly give you more area to silicone the tanks together, and you will not see them once the tank is setup. They may tell you that you don't need them that the thinkness of the glass and engineering in the tank if perfect, but I have seen the after effects of a panel popping off, or even the glass bowing...... Other than that I like frameless look.