Nice , the rock makes a real good focal point, if it were me I'd move it to the left a bit.However your amazon sword will get massive and probably outgrow that tank lol.The plants at the back looks like something I had named 'fountain plants' .They're non-aquatic though and will eventually die and start to rot your water.This usually happens around 3 months after having them.
As I was studying the plants I noticed how you concealed the filter with slate...Nice work
The front looks a little bare with plain sand and the few strands of "grass" on the front right corner looks a bit out of place. Perhaps replacing it with a few short plants (e.g. some smaller Cryptocorynes) will look better. DPs are very curious and they love exploring nooks and crannies so the more crevices and hidden corners the better. Plants with a bit more foliage or some holey/twisty bogwood will help creating that.
Do you know where your puff sleeps at night btw?