The best thing about the Graco travel system is the SnugRider Infant Car Seat Frame!

Like so many others, we registered for the Graco travel system.  Friends warned me that the stroller was so heavy I wouldn't use it, but I thought, "Not me- I'll appreciate the workout I'll get lifting it out of the trunk!"  (Now that the baby is here, I've never even attempted to put that stroller in my trunk- it's too heavy! haha)  The stroller (we call it the Cadillac.) is great for walks around the neighborhood, and we keep it in our entryway most of the time out of convenience/laziness.  The car seat aspect is awesome- he sleeps very well in it, and the straps are easy to adjust.
Before I became pregnant, I never even knew the Car Seat Frame existed, but as we were registering (and I became acutely aware of what baby products women were using in public), I noticed that everyone had this!  What sealed the deal for me was seeing a woman pushing it through the grocery store with ease and keeping her groceries in the basket underneath.   Then I saw another woman doing the same thing two aisles over!  I felt a bit frivolous because once he grows out of the infant carrier, the frame will be useless, but I knew I needed it.
Now I am lost without it!  It is super lightweight and turns on a dime (which makes it much easier to move around a store than a cart).  The basket underneath holds my huge diaper bag plus much more.  The lady at the Target checkout yesterday couldn't believe how many items I pulled out of there!
The one negative is that it takes two hands to pop it open.  There is a red plastic piece on the side that  snaps together when it closes to hold it all together.  It can be tricky to push apart, and there have been a few times when I couldn't get it open, which is slightly frustrating in a store parking lot when the baby is getting hot in the car.  (I've learned that if you hold the stroller with the red latch on the left, it snaps open much easier.)  However, it easily collapses with one hand which makes for a quick escape during a shopping meltdown.
I would advise no one to register for the Graco travel system without the Infant Car Seat Frame!

You can get it here!