Huge = safe for a reason

The Frontier is a combination harness-to-booster seat offering harness restraint up to 80 lbs and booster up to 100 lbs.  It has armrests, cupholders, and plenty of padding.  It can be installed with LATCH connectors or by one of two belt paths.  In keeping with other Britax products, this seat feels solid and sturdy - no cheap parts here.  The size is both an asset and a detriment; it is a very large seat and is somewhat difficult to install in smaller vehicles, but also be comfortable and safe for the older child.  It's a great value, as you can use it for so many years of your child's life.  And most importantly, you can safely keep your child in a 5-point harness up to 80-lbs.

As with any seat, it is worth carefully reading the manual to be sure you are installing the seat correctly.  Britax manuals are well-written and easy to read, with clear photos of every step.  Although this seat confused me at first, one glance at the manual cleared everything up.  Alas, it's not so easy to install in a Jeep Wrangler due to its size.  Also, my seat belts are just a little too short to use that installation method in harness mode.

In terms of aesthetics, the cover is well-made and attractive, with soft and quality-feeling fabrics.  The belly pad feels a little cheaper than the one on our Marathon, but the cover itself is very nice.  The shoulder pads are sewn closed, unlike the Velcro-closing pads of older Britax seats - so a bored child can't remove and lose them.  The cupholders are somewhat strange, holding only small cups and at a very odd angle.  They don't even hold a 20-oz soda bottle.

The fit is very good on my 27-lb, 38-inch son.  The one-hand harness adjustment is awesome - no more having to remove and rethread the belts as with our Marathon.  The center buckle can be installed at 3 different depths; again, a feature sorely needed by the Marathon.  Finally, no more having to sit on the buckle!  Also, the buckle is stiff enough that my child can't operate it by himself, so I don't have to worry about him getting out as we drive.  Unfortunately, buckling him in is a pain, as the buckles slide down to the ends of the straps
and into the holes.  You have to dig the buckle out every time.