There's only 2 of my exs that i would redate..even if things ended on bad terms..people learn from mistakes. The only thing you shouldnt go back to is a cheater.

If you realised you were better off as friends then a couple..why havent you seen him in ages? clearly you werent that great of friends otherwise you woulda stayed in touch..I'd say go for it to be honest.

Dating an ex after a few years is just not on, rebuilding those feelings is not worth the trouble.