I actually enjoyed the amount of dialog that's in Ground Zeroes, it feels more genuine and grounded. MGS4 could be titled "Talking matches, the Videogame". Seriously, the conversations in MGS4 are so long winded that the seriousness and gravity of those conversations are diminished. I would actually prefer if Phantom Pain is just as brisk as Ground Zeroes in that regard.
As for the Kiefer vs. Hayter thing, I prefer Kiefer. Its nice to have something new and different, Big Boss feels like a different character now, and a better one at that. Some of the fanbase for Metal Gear seem rabid when it comes to Hayter and Solid Snake in general.