We have a MaxiRider too, but I'd recommend the AHR model as it can grow with your child. We bought our just as they were starting to bring them out and the store staff didn't really know much about them, and we've only just realised that what we asked for isn't what we got sadly.
The only probs with them is that they are the most exxie and they are very wide. Kmart and BigW sell a similar seat that has the same features but is much narrower.