Another update, I've finally got around to upgrading his living quarters.
Inspired by several threads on here, and his behavior whenever I gave him a huge tub to swim in, I decided to do a predominantly water setup (it's about 12 gallons).








That's a 40 gallon breeder with a glass divider a little more than halfway in (favoring water) at 7" high. The top edge of the glass has been coated with silicone to keep it smooth.
Water's kept clean by a fluval 305 canister filter, and warmed by a heater. Flat rocks provide variable depths (which he seemed to need at first, but now he's comfortable at even the deepest points) and ease of exit/entry to the land portion.
Half of the top is covered with glass, and the other half screen. It's being lit by a 75 watt basking lamp, and a full spectrum flouresent light.

Already I've noticed him being more active, defensive, and even doing things like jumping into the water from the land portion and then completely submerging underwater for a minute when startled. He seems to use every bit of the tank, and has become much more interesting with the greater amount of space.

Currently keeping an eye on the water parameters. The filter has been cycled with an existing tank, but I'm sure a pyxie is a huge bioload in comparison.

Here's a couple more pics: