Yeah, the delivery is fine, outside of the odd way that Takei pronounces "nostalgia," but that could've easily been fixed in a looping session. The stilted dialogue definitely needed a polish before shooting, though. I'd say that's the more likely culprit for the scene being trimmed. "Any chance to go aboard the Enterprise, however briefly, is always an excuse for nostalgia." Who talks like that?
Heck, most of the odd omissions in TWOK can probably be attributed to something awkward about the scene. I'd say we lost the dialogue revealing that Peter Preston was Scotty's nephew due to the weird "Midshipman, you're a tiger!" line that Shatner had. I think there was something similarly odd in the Kirk/Spock exchange that revealed that Saavik to be half-Romulan.
I just watched the bit at the end of TWOK that hinted at a Saavik/David flirtation, and it's also a clunky scene. Kirk says to Saavik, "I believe you know David Marcus." Um... yeah, Kirk. She only spent a couple of hours stranded in the Genesis cave with him. They've met.
With deleted scenes, you usually watch them, see something interesting about them, but you can also usually get a sense of
why they were deleted. Check out the "That young man -- he's my son!" exchange between Kirk & Spock while they're climbing ladders towards the end of the TWOK Director's Cut some time. The way Nimoy says "Fascinating" in response to Shtener sounds utterly indifferent and downright sarcastic. I think I recall reading that it was the very last scene shot for TWOK, and it shows.