I bought this when my boy was a puppy, now, even full grown at 15 lbs. he still likes to use this seat.  He is over the weight limit for the product, but still fits in there nicely.  I still use this for short car rides, and put him in a larger seat for long distance travel.  But, again, that is only due to the fact that his currently weight puts him over the limit for this seat.

Pros: Fits nicely in between the front seats of my SUV, straps to each seat, and to the arm rest.
Cons: when I tighten the strap that goes around the arm rest, sometimes the buckle gets in the way of closing the arm rest.