Already a LOT of good answers here.
I own several KJV bibles (all fairly old) and I can tell you, my opinion, is that like was already said by po18guy, it is a good translation: The RSV-CE is based on it. However, like he says, the language is kind of TOO archaic. The D/R bible by contrast, which predates the KJV by a few years, went through some updates (in 1750) then again in the later editions, so that the text, when compared to the KJV, is easier to follow and read. But how can you improve on the KJV Psalm 23? And there are other passages that will live on as English classics. (like all of the KJV bible passages found in Handel’s Messiah.)
Regarding the Deuterocanon; I have made a bit of a study on why it suddenly went missing from Protestant Bibles. The main culprit was the Bible Societies of both England and the USA, in the early 1800’s taking hard line, anti-Catholic stand which struck them from their bibles, not just for commercial reasons (which itself was a good argument in their view,) but also for the sake of various fundamentalist sects which the Bible Societies catered too. But oddly, because the KJV was the “authorized” Bible in English, THAT was the Bible which all of the Bible Societies printed in super-abundance back then, minus the deuterocanon. Eventually it became controversial to even include them in the KJV bible, despite the fact, that it had ALWAYS been included historically speaking before.
Interestingly enough, the original KJV, at least for the first couple of hundred years, had even MORE books in its deuterocanon (Apocrypha) than even Catholics recognize, like Esdras 3 & 4, which used to be included with Latin Vulgate Bibles!
My own feeling is that the KJV bible is a little too archaic for devotional reading (since I wasn’t brought up with that text) so I prefer the D/R bible.