The best advice come from actual milkers
A long-time user of the Udderly EZ Hand Milker just purchased the Ultimate EZ Milker, and passed along a noteworthy observation.
Bonnie McQuatters from Otis, Colorado noticed that goats with small teat holes do better when the smaller 18-ounce bottles are used. She says these bottles draw the milk much faster because the smaller bottles require less vacuum to start the milk flow. Bonnie is one of the milkers featured in the video on the Udderly Ez Milker goat page.
Another happy customer, Susan, uses the large red inflation, which can be seen in this blog post, because it gives her better suction and more milk flow.