Diono Radian RXT vs. Britax Roundabout

How does Hiking Baby get to the trailhead? In his safe car seat of course! Car seats are a tricky business. Most importantly, they need to protect your precious cargo, your little one, while also being easy to use, multi-functional, and ideally grow with your child! Today we’re taking an in-depth look at the Diono Radian RXT car seat,

Hiking Baby’s Car Seat Evolution

As an infant, Hiking Baby used a Graco Click Connect 35, which was very easy to use and “clicked” right in to his everyday Graco umbrella stroller. He could stay asleep while I simply removed him and the car seat from the vehicle. Then, he graduated to a Britax Roundabout Convertible Car Seat when he got too big for the infant seat. However, I have found the Britax Roundabout extremely difficult for loading and unloading since Hiking Baby is still rear facing. Plus, Hiking Baby couldn’t see out the car windows (see images below).

Hiking Baby not able to see out with the Britax Roundabout XE 6.1 car seat
Britax Roundabout XE 6.1: Hiking Baby not able to see out with the Britax Roundabout car seat
Hiking Baby enjoying the view from the Diono Radian car seat

Compelling Features of the Diono Radian RXT

The Diono Radian RXT has several appealing features that prompted me to make the switch:

  • Rear-facing (i.e., safer) for longer. It can be used in rear-facing mode until Hiking Baby is 45 pounds (most car seats max out at 40 or lower). Note, Diono makes another car seat called the Diono Rainier that maxes out at 50 pounds in rear-racing mode, but it is pricier.
  • Will last for entire childhood.  The Diono Radian RXT can be used in forward facing mode until Hiking Baby is 80 pounds, then used as a booster all the way up to 120 pounds!  Even the sides are expandable.
  • Sturdy.  Built with a steel-alloy frame.
  • Slim design.  While I don’t need this feature, 3 car seats can fit across the back seat of a vehicle.  It also helps make the middle seat more usable.
  • Seems comfortable.  I haven’t sat it in myself , but the body cushions with memory foam look and feel comfy!

The Set-Up

For any parent who has set up a car seat, you know to always allocate a solid hour. It was no different for the Diono Radian RXT; however, the instruction book walked through the steps, and when those weren’t clear, the online Diono instruction videos were also helpful.

The Diono Radian RXT out of the box and folded. Nice and slim for storage or travel :)
The Diono Radian RXT out of the box and folded. Nice and slim for storage or travel 🙂
Easy to assemble, including moving the buckle!
Easy to assemble, including moving the buckle!

Specs of the Diono Radian RXT vs. the Britax Roundabout:

Diono Radian RXT Britax Roundabout
Diono Radian RXT Britax Roundabout
Price: $299 $137
Unique Features:  

  • Slim design.  3 can fit across back row of vehicle
  • Foldable (helpful with storage or airplane travel)
  • Nothing stands out as unique except the relatively low price.
  • Lose a lot of legroom in front row when the Diono Radian RXT is in rear facing mode.
  • Nearly impossible to adjust harness (to loosen it) once it is in the car.
  • Child cannot see out of car when in rear facing mode.
  • Need to buy yet another car seat/booster when the child outgrows this one.
Weight: 27.5 lbs 17.6 lbs
  • Steel alloy frame
  • EPS foam lined
  • “impact stabilizing steel frame”
  • EPP foam lined
  • 16 inches deep
  • 17 inches wide
  • 28.5 inches high
  • 18.5 inches deep
  • 26 inches wide
  • 21 inches high
Can it be folded?: Yes. Does not fold.
Baby Size Limits – Rear Facing: 5-45 pounds  5-40 pounds
Baby Size Limits – Forward Facing: 20-80 pounds 20-55 pounds, up to 46 inches tall
Baby Size Limits – Booster Mode: 50-120 pounds; 57 inches tall No booster mode.
Ideal buyer? Someone who only wants to buy one car seat and get good long term value by using it throughout the child’s growth phases.

When rear facing, it may not fit in all cars because it requires a lot of space (i.e., fit well in a Subaru sedan but not in a Jeep Grand Cherokee that has limited back seat legroom).


Someone who can’t afford to spend more on a car seat.
 Setup Process:  1 hour.

Easy to adjust harness.

1 hour.

Nearly impossible to adjust the harness while it is in rear-racing mode in the vehicle.


Overall, I am very pleased with the Diono Radian RXT and plan to keep it as my primary car seat for Hiking Baby.

Safe driving and happy trails!

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