I've stayed at Riverside. I'm intrigued by Coronado. One nice thing about Coronado is that there seems to be more on-site dining options in case you need 'em. At Riverside, there's the food court and a sit down restaurant that's only open for dinner (which is "shared" with Port Orleans French Quarter, plus pizza delivery. Coronado, not only are there more places to eat you have a full room service menu. If you either plan to or wind up needing to spend more time at your hotel, this comes in handy. To wit - our last vacation was late August 2014. It was one of the hottest if not THE hottest summers on record in Orlando (and everywhere). So a lot of our plans to go to parks in the morning, rest in the afternoon and then go back to parks at night had to be revised or else we'd drop from the heat. We wound up spending more time in the pools (we stayed at Bay Lake). We arranged for more sit down meals in the Contemporary and other monorail resorts so it wasn't so uncomfortable getting there. And then back to the pool or a super early bed time so it was easier to get to the parks and use morning extra magic hours.
So if you wind up in a similar situation, or maybe someone in your party gets sick and can't go out, having onsite dining options and room delivery are nice options. As well, the main pool and playground are supposed to be top notch. And there's an on-site gym and an on-site club if you've a hankering for health or nightlife.
The main negative with Coronado is that it does cater more to conventions than the other moderates (while still being totally family-friendly). So you might see more suits and people walking around with binders and talking shop. I'm sure it's easy to ignore.
Riverside has about 180 more rooms. Still a very nicely themed main pool and 5 quiet pools (I think Coronado only has 3). Riverside has boat access to Disney Springs (as does French Quarter, Old Key West & Saratoga); Coronado does not. If you like shopping or plan to do anything like go to Cirque or bowling or take in a movie, not only is the boat a nice option, considering the work still being done in the Springs areas it might be necessary. Even buses might take longer to get to and from versus buses for now, just due to the extra traffic construction necessitates (which of course might be done by the time your trip begins).
Were I you, I think I'd opt for Coronado. But I'm not. Which is a shame because I could have really used your PIN number.