SA 2.6.6261 and WOT work well together. The SA safe search icon and the WOT icon do not always agree (not surprising I suppose). In fact, they disagree surprisingly often. WOT ratings seem more conservative than those of SA, i.e. WOT shows more reds than does SA. SA does occasionally show a red where WOT shows a green.
I like the assurance that two greens gives me that I can browse a web site with confidence. The value of using SA and WOT together is worth more than the sum of the parts.
To see the full effect, try searching google for warez (its like looking at a rainbow).