Non Monatomic waveform, practically, how important?

Has anybody run test cases against popular simulators to determine
how important/sensitive monotonicity is to:

1) Convergence
2) Accuracy

We are frequently running into models with non-monotomic features. The
simulator
vendors recommend that models be monotomic and I believe the IBIS
spec demands it. Screening these features out is time consuming and
testing the resultant model is even more time consuming. IBIS simulators
generally do not have the knobs that SPICE simulators do. Is there a
mathematical reason for this, or is it more a customer issue?

Anybody have a few pearls of wisdom on this? What is the history behind it?

Nick Krull
StorageTek
11/10/98
Received on Tue Nov 10 08:34:42 1998