The only negative comment i can make is that the dimensions are a little off, we ordered the twin size but the mattress was a little small from the sides, menaing the frame has some issues with sizing. 
The platform is very solid for our 5 year old boy. 
We love it except the fact that is a little off in the measurements. 
Wayfair has really great products and I buy frequently from them with and never had an issue. 
Do yourself a favor and measure the mattress before blindly buying one online.