michpunk - I had the same experience, figuring out the theme before I'd solved any clues (though I had a variation with 3 different items in mind). As you say, luckily that didn't detract at all from the enjoyment of solving the rest!
I'm ashamed to admit that - perhaps buoyed up by that early PDM - I was utterly convinced right from the start that 5A was HOBO NEST, despite it (unsurprisingly) not being in any dictionary other than Urban. But it seemed to fit the clue so well...