Westlaw Canada has added some search features:
1) Did you mean? If you misspell your keywords in a search (e.g., "fiducary"), the system will prompt you to see if you meant the correctly spelled word (e.g., "fiduciary"). Interestingly enough, the misspelled "fiducary" still had 5 results which raises the issue if one should always truncate the term to "fid!" (this recalls a library school exercise I used to assign in the old days prior to there being online citators for UK cases – the exercise had students "note up" the famous Jarvis v. Swan Tours decision. I had one student that found one extra case because, for whatever reason, he had truncated "swan" and one of the decisions had it incorrectly with an extra "n", as in "Swann").
The "Did you mean?" is likely a useful feature and is something Google users have come to expect (admit it, like me, you go to Google and type in a difficult word to check its spelling).
2) Add Related Terms. Simply typing in: << "fiduciary duty" /8 director >> prompts the user with a small gray box of related terms (see screenshot below):
Some of the additional terms offered are various synonyms or related concepts such as officer, board, agent (for the director concept) or obligation, fiduciary relationship or trustee (for the fiduciary concept). You then click on individual words or can (although unlikely) choose the "select all" to add the words to your search. However, care must be taken when adding any words to your search to ensure your search remains properly constructed.
Overall, a useful feature but likely of most use to less experienced researchers.
3) Results Plus. A feature that was long available in the States on Westlaw was "Results Plus" that used fuzzy logic to recommend additional results when your intended search query has zero results. The principle here is a good one – never leave your user with no results – give them something. However, I have found in many situations the Canadian Results Plus have not been that useful (although I did click through and use them on one occasion).
4) Caselaw Citation Frequency. When noting up cases on Westlaw Canada, you now have an additional option of sorting the citing references by "most cited" (a feature that CanLII added some months ago). This is a common bibliometric analysis technique used in medical literature so it is nice to see it being applied in the legal industry. I am not sure if it was CanLII who had this idea first with Westlaw Canada reacting and adding it to their database. If it was, I think such healthy competition is useful. By way of simply comparison, in checking the citing references on each of CanLII and Westlaw Canada to Semelhago v. Paramadevan,  2 S.C.R. 415, CanLII had 143 citing cases with Westlaw having 197 citing cases (with an additional 30 citations to secondary content). Of the citing cases, CanLII had United Gulf Developments Limited v. Iskandar, 2004 NSCA 35, as the most frequently cited case citing Semelhago (43 times) with Westlaw Canada having United Gulf Developments Limited cited 51 times.
The obvious point here is that frequency of citation can be an important indicator of the strength of your precedent.