After reading through the codex, I'm intrigued by these guys. They seem like an interesting unit to use, but with a major flaw if the enemy hides in the same terrain. Then I had another idea- what if during deployment you used Spore Mines to saturate the terrain, to keep the enemy out? This may not even work, and it may not be a game winning strategy, but I'd like to give it a try.
I was also thinking about their morphing and when you'd want to use it. What I was thinking is on the charge, use the +1 T morph so you win combat, but not by a landslide. This way the enemy won't run and you won't be stuck out in the open. In the opponent's phase, use a more offensive morph to hopefully wipe out or break them. Once again, I need to test this so it may not even be a viable strategy.
They seem pretty easy to model, the feeder tendril heads from the Genestealer kit are all you need. Anyone had a chance to try these guys out yet?