I'm working with our SaaS customer service and good support guys are always natural on using these two words when a customer is looking for an affirmation.
Just think that this is a good metric to add and see how specific words help conversions and upsells for non-customers. Hopefully there's something more automated that I can use to measure, though.
I'm looking at your site (menutail.com) + competitors and unlimited is already an established plan in your market. Should you break this market-established plan/packaging?
Giving a number (regardless of the amount) can give an impression of limiting a user. Conversions (theoretically) may e affected (+/- 2%) specially when a customer is comparing between similar pricing / same feature products.
I would be happy to help you out on your AB testing when you think it's time. Like to see how this goes. :)