That's entirely up to you. It's only possibly a benefit if you find you need roads that are missing in your current maps. Even then, there is no guarantee that the updated map will have the data you want.
I updated my maps once and found that roads constructed several years ago were still not in the data file, so it was a complete waste of money.
I'm not willing to pay, again, until I can confirm the update actually adds value, in my area. I've asked Infiniti/HERE and their response was not helpful. They told me I had to buy the update to see what changed, they can't confirm any specific changes or even if there are changes in my area, and if I open the package I cannot return it.
No thanks.