Mira runs on the lower-end of the spectrum. Nothing wrong with that, just that it won't last as long nor have the same features as your mid-to-higher-end brands.
Wet test the spa. If it is not comfortable, your questions on it are irrelevant. Spas are about comfort, comfort, comfort;
COMFORT: How does it fit your body?
COMFORT: How doe the jets feel?
COMFORT: Are you comfortable with the price?
If NO is the answer to any of the questions, that is not the spa for you.
I hope this helps. Good luck moving forward.