The best way to provide optimal trademark protection for a logo consisting of both a word and a graphic element is to register the word as a word mark and the logo separately as a figurative mark. A word mark gives you the broadest protection of the word, regardless of graphic elements that are not being taken into consideration in a case. Of course, the word you want to protect must be sufficiently distinctive. One additional advantage of a word mark is that any future changes to the logo will not affect its validity.
The advantage of registering a figurative mark separately to a word mark is that it protects the combination of the graphic element and the word. If the graphic element might be used separately, it makes sense to also register it without the word (a good example of this is the Nike Swoosh).
If a figurative mark consisting of both a word and a logo contains a distinctive word, this will often be more dominant than any graphic elements if comparisons are being made under trademark law. So why is it wise to also register the figurative element as a trademark if you have already registered the word mark? The following opposition provides an answer to this question.
The famous Paul Smith trademark filed an opposition to a trademark entitled John Smith. The European Trademarks Office agreed that the first names are common and the surname is identical, and this alone is enough to demonstrate a visual similarity. But the fact that John Smith's chosen font was identical to that of Paul Smith greatly increased the visual similarity, and the European Trademark Office granted the opposition.
In this case, Paul Smith would have won even without a figurative mark. But suppose the opposing party had filed a trademark for John Smith. There would have been much less similarity between the words and the graphic similarity might well have been the decisive factor.