So, CoD:MW2's plot, then
Metal Gear is different than any other game storytelling out there, it's strangeness and japanese weirdness makes Metal Gear it's own genre of storytelling, like @shinobi2u, said sometimes it is really damn silly and sometimes it is really philosophically deep and makes you think (like the War Economy in MGS4, which is basically the most horrifying thing I have ever seen in a media ever) and some really silly stuff like Otacon's family ...
And each MGS game has its own essence and style, like MGS3 was basically a james bond movie while MGS4 was something else entirely.
Is the MGS story actually worth getting into? My understanding is that it's fairly basic (CoD-level stuff,) at best.
MGS is worth getting into imo and it is definitely not basic COD-level generic stuff, it is a story of political intrigue (with a little bit of weird supernatural japanese bullshit) but with really interesting characters and moral lessons learnt throughout the series.
MGS2 however was a mad game though, but it had an interesting story involving the patriots AI and some really prophetic predictions by Kojima back in 2002.
Keep an open-mind and try the series out, damn lizard, you may actually like it