“The RadianRXT is a highly versatile car seat that could be the only seat you’ll ever need. It comfortably seats rear-facing children from 5-45 lbs, forward-facing children from 20-80 lbs in 5-point harness, then converts to a booster for children up to 120 lbs.”
First impressions of this car seat are daunting to say the least. I pulled it out of the box (a big box) and found I had to dig for the instructions right away. It comes in the collapsed mode, which allows you to attach straps and carry it as a backpack, very handy for traveling, say, on an airplane. By the way, this seat is fully airline compliant, so you shouldn't have any trouble bringing it on a plane.
Anyway, as per the directions, the base of the seat folds out for use, and does so via a simple-to-operate latch. The back of the car seat holds all the various LATCH straps and belts needed for installation either rear- or forward-facing, as well as a seat belt clip for cars built before 2001 that do not have a LATCH system. Also in the box are the backpack straps previously mentioned, as well as the infant padding you can see in the picture above, which will nicely snug in your newborn. Our son is now about 20 lbs and too big to need the extra padding.
This Radian RXT is somewhat large, as you can see. Given that it can hold children all the way up to 120 lbs (which is heavier than some adults!), it should be. The headrest portion is adjustable so that the aluminum-framed head supports align correctly with your child's head.
Though tall, the seat is not especially wide, a feature Dioni says allows this seat to be installed 3-across in a vehicle. The construction is very strong and durable, composed of both heavy plastic as in most car seats and aluminum framing in certain places.
The straps are all adjustable of course, and this was the fastest part of setup for me, in contrast to many other car seats that make you remove covers and padding and whatnot; this was very straightforward to adjust to our toddler's height. A nice feature that complements the adjustable shoulder straps is the tensioner at the front of the seat which ratchets rather than just pulls, so you don't risk getting it too tight all at once when fitting it to your child.
It's a big plus to have a seat that you can take your baby home from the hospital in and not have to buy another seat until they're big enough to not need one any longer, so I was looking forward to installing it and trying it out.
Installing the Radian RXT turned out to be very challenging with our two vehicles that I tried it in. The big disclaimer here is that unfortunately we don't have a modern SUV or minivan, so installation was doubtless more difficult than it would have been had we had one. I first tried installing it in our 2000 Isuzu Rodeo, which unfortunately does not have a LATCH system, and after struggling with it for about 30 minutes and reading the directions over and over, ultimately had to give up. The design of the seat is such that the belt path under the seat is a closed tunnel, which first of all means you need small hands to be able to thread the belts through, which wanted to get hung up inside. But once I got the seat belt through, a larger obstacle cropped up. Because the belt tunnel is so low and closed off from the top (unlike a traditional car seat base), I was unable to tighten the belt enough because the car buckle of course cannot bend around the angle of the tunnel. This was with the rear-facing base attachment properly secured, but it was still as if the belt tunnel was too low to be able to tighten the belt enough. Compounding this in a car without a LATCH system is the fact that you have to secure the belt clip and then fasten the seat belt. However, with the Radian, there was absolutely no way once I secured the belt clip to snake the tightened belt back through the tunnel and clip it into the buckle since you usually have to have lots of leverage to do that, and I'm sorry, but my fingertips just aren't strong enough to manage that.
So, on to option two, the BMW 3-series sedan. It's a 2001, so it does have a LATCH system fortunately. However, given the size of the Radian RXT, I found it couldn't be installed behind the driver's seat, which is where the current car seat goes, because the high headrest of the Radian would have meant that the drivers seat would have had to go forward too far for anyone except a little person. I'm sure it would have worked okay forward-facing, but we can't do that until the baby is bigger.
So I finally got it installed on the passenger side of the car, but seemed to have a similar problem tightening the LATCH straps, due to the belt tunnel seeming too low. But in actuality, when tightened down as absolutely as I could, the manual says that when gripped at the tunnel, the seat should not move more than an inch in any direction, which it doesn't. However, it didn't seem right at first because shaking the seat from the headrest resulted in a lot of play. I guess this is to be expected since there's lots of leverage there, it's just that the manual didn't say anything about how much the headrest could be expected to move, and it seemed like a lot compared to the compact car seat we were currently using.
So the installation was rough, and took almost an hour before it was finally installed. But once it was in, use is as simple as any other car seat, and the quality of the buckles across the chest and between the legs definitely seems a notch above. As mentioned earlier, all adjust easily and connect positively. I also liked how once our son was in there that it seemed more open and airy than a traditional car seat while holding him securely. In any case, I see no issues with further use, and I know it will prove to be an excellent car seat whenever we finally do get a modern minivan.
The Radian RXT from Diono is very well-built and versatile. You could buy 2 or 3 car seats for your young one until they don't need them, or you could get the one Radian RXT. It's adjustability and quality of materials is definitely above par. I just wish the belt tunnel had been designed to make installation without a LATCH system less painless. That said, my difficulties with installation could just be that a fault of general ineptitude with car seats, mechanical prowess in many other areas notwithstanding, and not so much a fault with the seat. The Radian has lots of great reviews on Amazon, including one I read from a lady who has two in her Honda Civic, so maybe it was just a bad combination of an older car and installing while tired. In any case, the Radian RXT is a great carseat and one that I know will be able to handle all the abuse a baby/toddler/child can throw at it.