Do yourself, It's easy, if you aren't sure about something in the instructions there are plenty of videos on YouTube. I ended up going with a G2 because my plan was to stay in the 600-650hp range and stay on street tires (Continental EC02) as this my daily/canyon & twisties car. My car is an 18...
Hate to ask, but are you sure the RTD version that you purchased is compatible with Apple? The one I purchase 2 years a ago isn't, the newer ones are... I ended up just using an old Android phone that I had laying around or my laptop. Good luck though bro.
I've had BC racing for about 5 years and they've been great without issues. I just wanted to lower the car to my preference and improve handling, simple. This is my daily and I drive canyons every weekend. They have exceeded my expectations for the price.
If you're not launching on sticky ass tires then you're good. This is my daily with 80k mi, running a G2/120mm, Conti ECS02's, and coilovers. And drive like you have common sense in the rain.
For myself I bought a blower, new front lip, sway bars, and S650 headlights (love the DRL's). Haven't installed the sway bars yet, can't wait for the weather to clear up.