Yes, that is true. With my X-Rite i1Pro Spectrophotometer it is recommended to send it in once a year for inspection and re-calibration for a fee. It is not required, but if you do send it in they issue you a certification good for 12 months. This is good practice if you are selling profiles or working within a professional graphic processing arena but otherwise you could get away without this process for a few years. Eventually though, you would have to bite the bullet and have it done. Not sure what Datacolor does with their products, but bear in mind this only applies to the professional level instruments with X-Rite.
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Either X-Rite or DataColor are solid choices. If you aren't going to use the system to build paper profiles, calibrate/profile projectors, or other uses outside monitor calibration/profiling, then all you will need is the model that only has that one function and are relatively inexpensive.