+1 on the water bottle retainer- I only have one build like that, and just flew it for the first time last weekend, but it was pretty slick. Some drawbacks- need to substantially build-out the motor tube, and it doesn't work well for anything less than BT-50...to be honest, I think maybe mine is even a BT-55. I built it a long time ago, just never got around to flying. Kids thought it was cool, and, "just like the big ones!" meaning aeropack. Also- be aware that you'll need to install the igniter after securing the motor- sometimes it's easier for us to install the igniter first, before the motor due to fin arrangements and whatnot. If you have a complex tail end, test it first.
All my other LPR that aren't MinDia use engine hooks- I like 'em just fine.