Does anyone have a DI meter built into their RO/DI?

[Aquattro]

IMO, if it's included, fine, but I wouldn't pay extra for it. Any meter will need calibration at some point. With properly maintained pre filters, flushing your RO membrane and running DI resin that indicates exhaustion with a color change, you'd be good for years. If the TDS meter is going to give you peace of mind, fine, but it's money you could put towards something else.