We're a COBB Pro-Tuner just to be upfront with our bias..
If you want the ability to custom tune your 718 COBB is the way to go. Both tunes can make the same power, the difference is; do you want a canned one size fits all tune or the ability to customize? With COBB you can add any modifications you want to your 718 and a Pro-Tuner can dial in your map for you. APR does good stuff so the one size fits all approach may be what you want.
We tune Porsche's all over the world. This link outlines how we do it:
COBB AccessPort Tuning
Often we are tuning cars for local fuel grades or climate to ensure optimum and safe operation rather than max power. It's very common to not use a dyno, we're datalogging and working with customers at their pace from their location. They don't need to go to a workshop, we just ship them the COBB AccessPort and they generate logs and we send revised maps. Everything happens in the AccessPort, you don't need to take a PC or additional equipment with you.
The AP3-POR-010 AccessPort works on all 718s, you can install/uninstall it in 10 minutes at your home. Once uninstalled you can sell it or use it on another 718. Also, for a small fee COBB can change your firmware to enable use on any other Porsche. This does require paying the difference in price between the products of course.
Bottom line is there are lots of happy customers with both products so you really can't go wrong.