Why is everyone so negative ?
Surely an airline career is better in terms of job security and for the money but if he is not happy and willing for a new challenge then why not GA ?
From my small experience there are all kind of GA companies / owners / contracts... Hard do make a general statement on roster, job conditions, destinations..
But if you are lucky enough you can find the contract thats fits you, with a decent roster, homebase, salary and exciting operations...
Only hard thing will probably be to learn how to deal with changes all the time and to do everything by yourself as Proline21 said... But that's part of the charm of the job isnt it ?
Good luck anyways !