Well, "good enough" is subjective. Do you have a powered sub? If so that will help. It's really going to depend on your listening levels, room size, etc. Reading around a bit they arent super efficient and appear to be a bit power hungry so an external amp may be the way to go.
Best suggestion? Try 'em and see
The nice thing about Emo amps is you have a 30 day period you can return if you want.
My system: Yamaha RX-A3060, Emotiva XPA-2, Salk Song3, Salk Songcenter RT, Polk FXiA6, Rythmik FV15HP, Intel i7 HTPC running JRiver Media Center