The 33-year-old midfielder is the latest of Rangers signings in a transfer window which has seen Jordan Rossiter, Matt Crooks and Josh Windass join the Ibrox club.
The former Premier League man joins Rangers on a free transfer - the same as the others - after helping Burnley win promotion back to England's top flight this past season.
Barton was one of the Championship's best players in the 2015-16 campaign and his ability, along with his experience, should certainly go a long way to helping the Glasgow giants enjoy a respectable return to the Scottish Premiership next season.
Miller, who spent six years at Rangers, says Burnley players couldn't speak highly enough about their former team-mate, noting that he was an "influential character".
“Barton is likely to be the pick of the bunch though, and I do think he will be a top player for Rangers," he told The Sun. “I was on a coaching course with a few of the Burnley boys recently and they couldn’t speak highly enough of him.
“They said he was a really good player, a fit boy, and an influential character to have around the place. He will really help Rangers next season and he seems up for the challenge too, which is always great to see.
“Barton is a big character and I’d expect him to make a massive impact at Rangers.”
Indeed, this is not Barton's first rodeo and he certainly seems to have the personality, along with the talent, to be a major figure for Rangers next season as Mark Warburton's side look to challenge Celtic.