You would take avoiding action as you see best.
The alternative is to do nothing, which is silly. It is the "head in the sand" attitude so prevalent in GA - like the map+stopwatch being the "proper way" to navigate.
The inter-communicating TCAS systems used in airliners need to work that way because everybody has the system, and everybody is always (or nearly always) flying under ATC direction, which is assumed to be "right" (provide 100% guaranteed separation) so any traffic proximity is a dire situation where something in the system has already gone badly wrong, and is considered so serious - yet so rare - that a resolution based purely on a level change is considered sufficient.
In the GA OCAS context, excessive traffic proximity can and does occur during routine operations. Even if under a RIS/RAS, ATC will advise of traffic only according to workload. Therefore, traffic awareness increases safety and I cannot see a scenario where it is not worth having because it decreases safety.
One can certainly argue about the value for money. It is pretty poor. With ~ 1 midair per year in the UK, for some 20,000 GA pilots (the total # with valid medicals) that gives us some 400k annual hours flown. Nearly all of the mid-airs occur below 1000ft, so (unless one is into kerb crawling) the time window in which you might have one is exceedingly small.