This stand is worth the money. I eventually succumbed after using a cheaper X stand with my P85 for 1.5 years. In recent months the X stand was giving me back pain after half an hour of playing and often I'd have to lay down afterwards to recover! This stand is sturdy, made of solid materials, and, crucially, allows you to get your legs underneath the piano and have it at the correct height. It's important to make sure your stool is at the right height too, so that your forearms are parallel to the ground and your wrists just above the keyboard.
Since purchasing this, I've had no troubles with my back, playing has been much more comfortable, and the piano also just looks much better overall when on this matching stand. I'd buy this as soon as possible to go with your P85 as the price seems to be rising.