Very intuitive, slick and fast UI!
I still find it a bit difficult to visually scan the results list, particularly at full length, but I'm hoping the various filtering options help with that.
Idea for display: Make it a table, with words down the left and domains across the top:
| word | .bz | .nu | .us |
| ant | ✓ | | |
| awe | ✓ | ✓ | |
| ...and so on