Lasagna gardening is the best. Each year mine just gets better and better. I finally am able to plant root crops, now that I've built up a fat soil base. You're right about those squash bugs though. I also use DE and some neem oil when they get bad. And just like you, the biggest advantage for me has been moisture retention. I live off-grid and have no garden hose so watering is a big concern. Not so much with this style of gardening.