After Caustic Thought, Simon briefly worked with Townsend on his Noisescapes project, who then left for Los Angeles to play with Steve Vai.

After that, Simon returned with SYL, who achieved even greater success with their second album City (1997) with Chris Valagao Mina.

He is also the guitarist of Zimmers Hole, which includes fellow Strapping bandmates, Stroud, Gene Hoglan, and Chris Valagao.

Sovereign was written by Simon over the years leading up to the recording of the album, and features Simon on guitar and his old band mates Stroud on bass and Hoglan on drums, along with Steve Souza (Exodus) on vocals, and Glen Alvelais (Forbidden, Testament, LD50) on lead guitar.

In 2010, Simon was the touring guitarist with the band City of Fire, which includes Stroud and Fear Factory lead vocalist Burton C. Bell.

On October 27, 2012, Simon joined Townsend on stage at his Retinal Circus event, held at the Camden Roundhouse in London, where they played the SYL songs "Detox" and "Love?

From 2013 to 2016, Simon was a member of Scar the Martyr, a new project of Slipknot drummer Joey Jordison, as full time lead guitarist alongside Kris Norris.