Well, good enough when they were brought into SystemC business but definitely not now.
SystemC is with us for past 15 years and associated tracing mechanism too. But everybody knows how rapid ESL changed over past 15 years and I think this is the time when LWG might consider giving a thought on updating tracing mechanism which bring in digital, analog and TLM together - with various type of analog simulation especially under consideration.
VCD files were good enough but the file size easily goes over GBs during debugging a relatively big SoC, furthermore they are signal tracer which is gradually has become not that much SystemC business - why not thinking out a compressed binary standard.
I see everybody struggling with an updated language which has a backdated debugger and trying to curve out solutions on their own and as a result the situation is messy.
SystemC is the principal initiator in the ESL world - if LWG does not take initiative, nobody will and things will be messy.
Regards, Sumit