Yeah, MGS is IMO just as much about the gameplay as it is about the story, if not both. At the very least, I'm having a lot of fun both playing the game and watching its cutscenes.
And while the cutscenes may be rather long, I'd much sooner say that I'm waiting to see what sort of major exposition is around the corner than not. That last cutscene pretty much continued along two plot threads that had already been introduced earlier (the ones relating to Gray Fox and Metal Gear REX...also I know why the only person who's providing Snake with info on Gray Fox is Dr. Naomi Hunter), and then introduced Otacon's disturbing backstory at the same time.
Long story short: MGS definitely keeps its plot focused. I can think of a perfect example of a game that muddies an (IMO) otherwise good story by having pretty much no focus (along with at least one or two other major issues).
Also, all of the major exposition cutscenes have happened after clearing a major objective - the last two both taking place after boss battles, to boot. This is something I point out to as a major strong point of the storylines in Zelda games - that story progression is almost always a reward for clearing a major objective (often finishing a dungeon), and it's nice to see that MGS is at least somewhat comparable even if its plot is more expository and the game is obviously more story-heavy.
Speaking of boss battles...I kinda like how all three of the bosses I've fought so far didn't die when defeated - and I know all three of them (Revolver Ocelot, Vulcan Raven, and Gray Fox) play a major role in the rest of the game's storyline. Plus there's the whole thing about Ocelot getting his hand cut off by Gray Fox. I KNOW WHAT THAT LEADS TO...