I have used MT5, but now use Colormount and it works great.
I've tried the new Arista and it was AWFUL! It was terrible thick, very gummy and messy, and would always cause my prints to very slight come back up around the edges, even when coldpressed afterwards. Because I'm also using single weight paper, the gummy bumps I would get from the tacking iron would show as bumps on the surface of the print.
I do not suggest using the Arista.