What I have learnt is:
don't use 5 min quick cook pasta (too soggy)
don't use frozen cauliflower (way too soggy and unpleasant texture)
do remember to reserve the pasta water (though you must use a massive pot to have 500g of pasta and a whole cauli)
don't just add in water instead (bleurgh)
wait until the bacon is properly crispy otherwise its doesn't 'whizz' as described
I will probably try again as I have seen good reviews on other blogs but heed my warnings and follow the recipe exactly as suggested. I feel like just making a white sauce and a ton of cheese on the top would probably be better than a whole packet of grated cheese and a whole tub of creme fraiche. But watch this space...