There are three things that keep me a UC member (as much as I am chagrined by recent "enhancements"). In order of importance:
1) As a 1K I can add my SO on at a pretty reasonable additional cost. Hearing her happy while traveling is worth the cost of admission to me alone. As an example, she was heading LHR-ORD and I had SWU'd her into C. She made the mistake of going to the Y checkin and the agent flatly refused to apply the upgrade (which had cleared) because our last names didn't match. I had her go through to the *A lounge and they processed it for her noting that the "woman you checked in with" was a "known quantity" to them. She wouldn't have had access to the lounge without her RCC membership.
2) The IRROPS support is just flat-out superior (unless perhaps you're a GS with your magic phone number). Even if it is only once a year that a UC agent saves me from having to over-night somewhere or miss a meeting it is worth it.
3) Inevitably there are 2-3 times a year where I am stuck at an airport for half a day due to wx/mx/whatever. Having a quiet place to sit for 6+ hours is nice.
I shouldn't say this (because SMI/J will probably take it under advisement) but #1/2 will keep me a UC member pretty much indefinitely. Though, in fairness, my firm is picking up the cost next year (wasn't the case for the last 9 years, however).