Triangle speakers not for rock?

I was considering buying some Triangle Heliade's to match with my Onkyo A-9555 in my apartment, but heard they don't sound good for rock. I don't exactly know why though. Right now I have Heresy's which some might consider bright and little bass like the Triangles, but they seem fine to me for rock.
I got a pair and they do good for rock but as a monitor not huge in the bass dept. They are bright but i use a tube amp which sounds better with them. Music listened to Stones, Sex Pistols, Neil Young, Pretenders, Talking Heads, Deep Purple, Who
They rock bi-amped as I have a Triangle T17FLV 608 Mid bass and they sound great with any music, fast and open. not too bad without a sub.
I biwire mine and they sound great. I just bought a bunch of remastered cds and they have terrific detail and lush decay. (They were cds by the Pretenders, Peter G, Eno, Bowie and Lou Reed. My Radiohead and Janes Addiction likewise sound great.