[Elecraft] 10 mHZ external reference VS the K3S's optional KTCXO3-1

[Doug Hensley]

I've been following the thread on using a 10 mHZ external reference and the prospect seems both affordable and at least initially fun BUT I'd like to ask is it really a practical improvement over Elecraft's available KTCXO3 internal 1ppm reference?  Or is this just a way to achieve more accuracy at less cost than the KTCXO3 ?  Isn't the K3S better served with its own oscillator?  What am I missing here?
Thanks,
Doug W5JV / AFA6DL