And it's FREE. You can have every character, play every planet, get all the massive DLC's, without spending a single penny
A quick google search of both of these topics, focused on the last year especially, and you'll see reviewers and players who have played both games almost universally say Warframe is better, even at the bungie forums.
I'm not gonna make some huge drawn out post on this but I will say those of you who are turned off by Bungie's shady business practices with monetizing Destiny owe it to yourself to try out warframe. the games are remarkably similar until you realize how much deeper in every aspect Warframe is. You are a space ninja who was awoken mysteriously by your AI buddy. Your ship is your loading screen but you actually walk around it and craft weapons / mods inside of it, the Relays (towers) hold up to 60 players at once and is much larger than destinys, Trading wih other players, customizable clan bases, events that actually shape the world, there are 12 planets, 25 different classes (guardians) with 4 supers each. Melee combat with all types of weapons.
For anyone who hasn't checked it out or only played the early release you should definitely check it out again. it's more or less a different game because the developers have been great at adding updates, new parkour and melee systems, weapons, levels, UI reworkings, all of this which has been added for free....while destiny charged 20 dollars for content that was already on the disc.....with little to no gameplay or map additions outside of modes