Is a 2.5 year shorter tenure clock a benefit?
Getting tenure is (technically and in actuality) a promotion and comes with at least one benefit (not easily getting fired) and usually there is a (modest) pay jump. Whether you consider these benefits against the additional responsibilities that tenured faculty have (especially in terms of administrative/service work) is up to you.

A shortened tenure clock could be a good thing as it gets you that promotion sooner. It could also be stressful if you're at a place where the tenure hurdle is clear and you don't think you'll make it (e.g. 7 peer reviewed articles when you have only 2 in the bag and will only get 3 more done by tenure-time)

The best would be to have the option of coming up early -- but also the ability to delay your tenure bid and return to normative time -- but also retaining the ability to count all of your materials from your postdoc period in your tenure bid.  There may be resistance to this, though, as it might be seen as having your cake and eating it too.