Syrian loves it so much she sleeps in it!
My Syrian has had this for a good six months now, and she sleeps in it (filled with Fitch!) every night, and hoards in it (and sometimes pees in it - she tells me it's *that* multifunctional)
The base slides out - helpful because after a while pee got into it, and it had to be removed. The ladder is a bit steep for hamsters going down, and was eventually chewed, so that went. We rarely see her against the perspex, but ultimately what matters is that she thinks it's the bees knees for sleeping!