What is the impact of the Advisory Guidelines on spousal support?

In Yemchuk v. Yemchuk, 2005 BCCA 406 Prowse J.A. stated at ¶64, It should be stressed that the Advisory Guidelines are intended to reflect the current law, rather than to change it…I have no hesitation in viewing the Advisory Guidelines as a useful tool to assist judges in assessing the quantum and duration of spousal support...

Furthermore, in Redpath v. Redpath, 2006 BCCA 338, Newbury J.A. observed at ¶42 that, while using the SSAG is not mandatory as a matter of law, if the quantum of the award was substantially outside the range provided for by the Guidelines it could, in the absence of some explanation for the difference, constitute an error of law reversible on appeal: ...Now that they [Advisory Guidelines] are available to provide what is effectively a "range" within which the awards in most cases of this kind should fall, it may be that if a particular award is substantially lower or higher than the range and there are no exceptional circumstances to explain the anomaly, the standard of review should be reformulated to permit appellate intervention...