I think you answered your own question! If you use it as backup, and have a current chart in your hands, there's no need.
My little Garmin has a database that was wrong when it was "current".
Garmin/Jeppesen haven't fixed the errors in how they display European airspace yet, so there isn't a lot of point in spending good money to update it to something different, but still wrong.
You may find your 250XL has the same problem. Check - does it show Class A airspace round Heathrow? Does it show the Airways as Class A? Does it show ATZs at European sizes (2 and 2.5nm) or US sizes?