I've assembled my Toxicrene/Maleceptor kit as a Toxicrene, and it is pretty nice. A good sized monster, with big (and perhaps unwieldy on the tabletop) tentacles. 

A note about construction: The instructions default to the Toxicrene in the rearing up position, with one claw on a unlucky Terminator and the other claw up. The model can also be built with a lower pose. This is descriped in tiny print on the cover of the instructions. I'll admit I did not notice them until after I had assembled the body. Good thing I wanted the default pose.

It is important to let the arm sockets dry before attaching the tentacle arms. Otherwise they may push in and that is no fun. Alternatively, you could leave the head off so you can put your finger on the socket and hold it in place while you glue the tentacle arms on.
The fallen Terminator is a really nice touch and I can't decide if I am going to put it under the Toxicrene's claw or on a base by itself and use it as an objective. 
With a Dreadnought for scale
I'll get this beastie painted and unleash it upon the battlefield soon.

The Hive Mind Hungers
Now with even more Tentacles!