R10 upgrade?

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I've seen R10 tweeter upgrades to the Vifa (now Peerless) 1" dome. Is this a worthwhile upgrade?
I'm new to the Polk speakers after a recent craigslist purchase for $30. My R10s sound nice and balanced with the sub I'm running, but would like to improve on the highs a bit without spending too much.
Any thoughts or advice is welcome.