Project X is overrated imo, and he was just comparing the obscene amount of buy-able debris common in both maps.
But the detail that went into it. The hype was first of all amazing which when you start you get released into this giant facility where you wonder, whats in here, or here. The map yes is expensive but makes it so much more rewarding when you win. The objectives make it fun to have to search the map looking for these objectives going round by round trying to survive. It was also the first map that had the UGX UMP45(I know it was a problem for you but That was honestly a whole chunk of how I got interested in UGX in the first place at the time, of course cabin too

). Sure if your looking for a random fun map to play you aren't going to play it most likely, you are going to play something with a more arcade feel, but to me project x felt the closest out of any map to the original treyarch maps. Hell I didn't even know there was an easter egg with a perk in the map until 6 months after release. The way the map climaxes too, He used a very simple entity move script to move this whole stair case down from the roof, I thought that was really cool, It simulates climbing to victory as you are moving closer to the roof until you finally get to buy the helicopter and fly away. Anyways that's the experience I got out of project X, and because of it its always going to be one of my favorite maps.