Check em out - awesome band, only 1 album to their name so far. VERY Tool inspired, but IMO not copycats. Opeth's ex-drummer Martin Lopez (one of my favs) shines in this band, really gets to do some cool stuff he couldn't do with Opeth. However, I DO miss him in Opeth!!
Recommended tracks, all available on Youtube:
Fraccions
Delenda
Canvas
Savia
I'm telling you, if you like Tool, you MUST check these guys out!