My impressions:
The Maxi Cosi Rodi XR is very sturdy seat with nice deep headwings. The cup holder is excellent, one of the best designs I’ve seen, it’s easy to install and remove and the design makes it very stable – thus far we’ve had NO spilled drinks, and most cups & water bottles fit. The seat is easy to assemble, and has a built-in recline to help the seat fit better on various different vehicle seats. The height adjustment is a bit tricky, but not difficult.
The illustrations in the manual are excellent, and the explanations of vehicle seats and seat belts are really well done. The manual can be found here: http://www.maxicosi/.us/media/producthandleidingen/maxicosi/4358-4583.pdf
The seatbelt fit on my 55 lb, 6 .5 year old was pretty good, with the lap belt low on her hips. I tried her 48-lb best friend in it, and it fit him well too. They both said it is a comfortable seat, and Joy has no slumping issues when sleeping in it, although a smaller child might.
My major disappointment with the seat: belt guides are VERY narrow, and in my Suburban the belt tends to get pulled out and not retract, leaving a great deal of slack in the belt. If the seatbelt telemetry isn’t just so, a child who is inclined to move around could easily end up with the shoulder belt two feet from their chest. Because of this, I would only be comfortable recommending this seat to someone VERY CPS-conscious.
Additionally, the seat requires the vehicle seat back or head rest to be above the midpoint of the child’s head. For many families, this means the seat is incompatible with their vehicles. The seat does feel more sturdy than many boosters without this requirement, and it doesn’t fall apart when moved or tip when going around tight turns.
Overall, I really want to love this seat, but because of the small belt guides and the head support requirement, I can’t. I give it 3 out of 5 stars.  A few comparison photos of Joy in the Rodi, the Recaro Vivo and the Britax parkway (old style) can be found HERE.

Skaterbabscpst is a long time moderator at our Car-Seat.Org forums and has her own CPS website.  You can find our original review of the Rodi XR here.  You can also find the basic Maxi Cosi Rodi for sale.  It lacks a few features of the XR, but can be found for under $100.