G-tech Q’s are typically good drives. Personally I avoid LaCie for the same reasons as you apparently had. But all drives can fail – it could be too hot in your edit bay, or too dusty, or you got a bad batch.
How many do you have on a chain? Try splitting them up evenly. I might be wrong but I though 6 devices was MAXIMUM on firewire.
Also download an applescript to keep your drives from going to sleep while editing.