A closer approximation to MX Reds would be a really really light MX Black, and due to that, feel even smoother.
The MX Brown comparison is sorta close, but the Browns end up being heavier.
MX Reds are a really nice light switch for a board. Until I got my 30g Topre, it was my favourite light switch to type on.
Edit: The MX Reds on my board, when I measured them, are 44g as reported by Cherry.