Greetings to the forum. I'm a first-time Mazda6 owner, after coming across a CPO 2017 model with around 3K on it. Coming from a Chrysler/HEMI for the past several years, it's a big change but liking the car so far. I miss the torque/HP a little, but the 6 is fun to drive and the MPG is awesome compared to what I had before.
Congrats on your purchase. If you're missing the low-end torque then you may want to look into the ~$500 OrangeVirus Tune for our cars. Tons of members have it and many say that it really adds the necessary (albeit still nothing spectacular) bit of "oomph" on the low end, while maintaining good MPGs.