Had to take away my original post, published it accidentally while I was still writing it. There is a distinct set of pros and cons to both to me, which I will be listing out below:
Ability to make lists;
You can explain your rating system.
RYM has a very large community. Although it will be hard to make as much friends as you could have on AOTY, there is still a chance that you will find people that have a lot in common with your musical taste, or those that have really interesting recommendations.
Very poor design;
Some useless features (the musical map comes off as one of them to me);
Can be tasking to find new music for you, no matter the release date.
Minimal and charming design;
Listeners can find new albums with ease;
Friendly community (except for the Shazes that appear every now and then);
Some of the highest rated albums --AOTY’s cult classics, if you will-- aren’t even on the best of all time charts. Personally, I think that an album with at least 20 ratings should enter the charts. If anyone goes there --which I don’t know if most go there–, maybe they’ll find something that truly interests them.
Some features are unnecessary (like the top albums of the year feature, that appears on most profiles right now);
The interface for writing reviews isn’t as complete as I wish it could be;
The specific rating system can be a burden, but it’s optional if you want to adhere to that rating system or not.
Overall, I find more advantages on AOTY than on RYM, but I still like to use both. I think that they complement one another, and I’d still say that it’s worth having an account on both due to that.