I've only made this once, but it was awesome! I left out the spinach, and used mild sausage and regular cream cheese. My husband went back for thirds! I'll try a few more alterations next time for the fun of it.
This was a tasty dish, but it was a lot more work than I anticipated. So many of the ingredients need to be cooked and/or prepped ahead of time (cook the sausage, cook the onion, cook the noodles, defrost and drain the spinach) so it took a lot more planning and time than I thought it would. It also required using several different pots and pans to prepare this meal and since I'm stuck doing the cooking AND cleaning, I hate that :)
As I said earlier, though, the dish was yummy. So if you don't mind the extra work, it definitely tastes good. The only recommendation I'd make is that you only keep it in the oven uncovered for 5-10 minutes. I found leaving it in there uncovered for 15 minutes made the top noodles too crunchy.