PAGK are definately a great choice. I even run a unit in my Draigowing lists because of how handy Warpquake and acess to a RB is. Only no-no i see with them is weapons upgrades. Generaly buying the psilencer, halberds, or falchions is a waste of points. As for that matter, i have never found a good reason to take models with Falchions besides they look cool, so every once in a while i will pony up the points for them. As far as the Razorbacks go, the only mistake you can make there would be neglecting to get psibolt ammo for the HB/ACs. My favorite is the HBs at the moment. They are cheap, reliable vs infantry, some transports, and those pesky bikes/LSs/Venoms. True, they lack the punch of the LC or Assault cannon variants, or double threat of LC/PG. But their cost and decent range make up for it.