Difference in speed? Virtually none. (couple of hundred grams of weight could make a miniscule difference on an extended climb).
Shifting performance? New 10 speed Dura Ace will shift a bit nicer than 6 year old (prsumably 9 speed) Ultegra, but its not a big difference, and it won't meaningfully affect the bike's performance.
If you really want to drop $1000 plus to get an "edge": Deep dish carbon wheels.
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You could fall off a cliff and die.
You could get lost and die.
You could hit a tree and die.
OR YOU COULD STAY HOME AND FALL OFF THE COUCH AND DIE.