The Q7 is the latest model.
Q was the 1st model, followed by the Q10.
I put up a review of the Q7 here
https://www.pentaxforums.com/forums/pentax-q/233063-tokyo-story-pentax-q7-real-world-review.html
IMO, a boring check box style / textbook type camera review is just not going to do justice to this camera/system.
A real world review, along the lines of
"I brought along this small camera called the Q7, went places and managed to take pretty nice photos with it in all real situations where a photographer/traveler would have taken photos" shows it off better imho.
What's more to ask for from such a small/light/fun system??