Based on your review, here is what I like about this seat:
-EASY installation for parents who are not car seat savvy
I remember my shock when I first moved from the Graco Safeseat (amazingly simple, secure installation) to installing a RFing Britax with seat belt (which is actually one of the easier RFing seat belt installs, I have now found). The SmartSeat allows parents to become familiar with ONE, very simple installation method.
-Parents seem to looooove the "only seat you'll ever need" hook, as evidenced by the popularity of the horrible Dorrel 3-in-1s.
-Separate base for additional cars - parents who feel uncomfortable installing convertible seats should be delighted by this. Heck, I would be delighted by this if my child was transported regularly by a non-parent. I could install the very simple base installation (and show the care provider how to do it, with relative confidence that they could do it correctly). Then when dropping off my child, I would only have to leave the car seat rather than having to take the time to install it. I made the mistake once of NOT installing my child's car seat for her baby sitter, and returned to find it installed FFing with the LATCH straps through the RFing belt path.
-Due to the ease-of-use, I would whole-heartedly endorse this seat for a parent with a typical level of car seat savvy. I just think there is a much higher likelihood that this seat will be installed and used PROPERLY, every time.
However, I do not think this seat will really be that attractive for most c-s.org parents for a number of reasons:
-Not good for a newborn, which kind of defeats the "only seat you'll need" angle
-Seems like RFing limits will be low, due to the restriction on the harness slots that can be used RFing
-Makes a heavy and awkward booster, with questionable belt fit
So for those of us who are car-seat-geeky enough to actually ENJOY buying new seats and ENJOY installing and re-installing our car seats correctly, we wouldn't really get much out of this $300 seat.