Those look really nice.
Might I ask what kind of cuts you did for the joining, if any?
I'm going to be building some display cages this winter (taking a wood working class this fall). I'm looking at going 4'x2'x16" (external dimensions) - I want the 16" height because I want to put flourescent lights in, not for animals - but for me.
I'm thinking about using a single piece of 12" flexwatt in each cage.
For my Pyro Pyro (I have one now - er, soon, it's shipping in July when I can guarantee I'll be home to take delivery) I may go 3'x2'x16" since they don't get quite as large, but I'll do the 4' wide first to see what the temp gradient is like, in case 3' isn't enough.
Did you tile the entire bottom, or just where the flexwatt is?
I'm thinking about tiling the entire bottom. I'm also going to put a substrate dam on the front of each one and probably frame the glass (I want to use real glass, it looks nicer imho) in wood.
I helped my brother build his house - but that was pretty much just framing and roofing, so I want to build some skills with cabinetry before I undertake this.