Only about 1/3 the size of dvls, but enjoyed just as much I'm sure. I spend every second I can out there when I'm home. As far as the collared lizards go...yea, you can keep them out there, but they will eat offspring of your other lizards. I live in Illinois, so I keep my lizards in until it warms up nicely outside. Usually by that time, my females are all done laying eggs, and I don't have to worry about them laying eggs in the pen.
there are a variety of spinies...the larger ones would be overwhelming to feed in my opinion, unless you had some sort of large insect lure. Maybe DVL could male you a dead cat to leave in the pen...could attract lots of flies for the spinies to munch on. 
I have one yarrow spiny in my pen, and she seems to enjoy hanging out by the coreopsis flowers. She will eat up any insects that even thinks about landing there.
Best of luck,
John Eddington
This is an inside view of my pen...

This is an image that construes how I designed it as a feature of my deck.
