It's perfectly mediocre, which for a Bond film, is worse than being downright terrible. At least Moonraker, Diamonds Are Forever, and A View to a Kill are so completely ridiculous and stuffed with camp that they're actually really entertaining. Spectre is Craig's worst Bond film yet.
There's some good stuff in the first half of Spectre like the Mexico opening, the confrontation at Mr. White's cabin, and the train fight scene. But it all goes to shit once they arrive at Blofeld's lair in the desert. The sheer stupidity of trying to connect all of Craig's previous films with a half-brother Blofeld is just astounding. It's literally a plot point taken from Austin Powers Goldmember. Blofeld being a villain that goes to Kinko's to print out headshots of past villains and tapes them up for Bond to find is not menacing. How did anyone think this was a good idea? LĂ©a Seydoux does look amazing, but she has no chemistry with Craig and the script completely botches their relationship. A lot of Spectre's problems can be blamed on the poor script.
Casino Royale (2006) was such an amazing movie and it's kind of impressive how they've failed to build off of such a strong reboot. I partly blame Same Mendes, who is clearly a fan of the older Bond movies and wanted to inject many of the old tropes and jokes back into the franchise. I don't think most of it works with Craig's bond. It's also a classic Bond problem in that anytime they try to outdo themselves and "go big" they end up delivering an overstuffed mess like Thunderball or Die Another Day. Skyfall was a big success, and they clearly wanted to go bigger with more locations and gadgets while reviving a classic Bond villain. It didn't really deliver. Let's hope Craig's last film is a hell of a lot better.