I'll check on the forum when I get home, but there was a thread in the LM area describing them with level requirements. One of the new AOEs is late teen/early twenties and its an AOE that will also stun the dead. Most of the rest are between 30-43ish. The rez has a regeant requirement, so I hope the c/d on using it is fairly short (noncombat rez).
The lynx is an upper tier pet that doesn't have the armor/hp to tank much without you pouring health into it, but it does have a significiantly higher dps. Seems to also have a stealth mode along with some other special attacks and because of the possible high damage output can keep aggro a bit without special aggro abilities (unlike the raven that will rapidly lose aggro when playing solo).