What are some critical perspectives?
As stated earlier, WebQuests are not the best way to teach factual recall, simple procedures, or definitions. Since many curricular standards address content of that type, there are chunks of the curriculum that are eliminated from WebQuest territory.
Finding the time is the biggest obstacle to designing your own WebQuests. Your first attempt requires that you learn to use some new tools, and some teachers simply can not find enough spare hours to pull it off. The benefit, though, is that once you have made your WebQuest, most of your work is done. Once that occurs, you no longer have to worry about daily lesson plans or scintillating lectures. Relieved of the burden of being the main source of new information, you instead work with your students as a coach, thinking on your feet. Many teachers find that they like this role better than being the "sage on center stage."
Anne Worrall, teacher at Encanto Elementary, talks about how WebQuests can be used for students with a variety of basic reading levels.
WebQuests also require that students have a certain level of reading ability, unless one is careful to find highly visual sites or has an adult available who is willing to read the screens to the students. This means it's harder to create a good WebQuest for children younger than the third grade or for those with language or reading difficulties. Again, these limitations can be overcome by paying special attention in your design of group work, but it is a harder fit.
You should also be prepared for those who feel that classroom learning should be focused on facts and content -- and who oppose inquiry-based learning more generally. They may deride WebQuests as "fluff," since they emphasize critical-thinking skills rather than particular information.