Wikitravel articles, with rare exception, have '''no single author'''. Multiple contributors work on the same page, so it becomes confusing to understand who "I" refers to.
You don't need to qualify your opinions with phrases like "I think", "I found", "I enjoyed", "seemed to me", "in my opinion", etc. If you actually think or feel something, plunge forward and just say it. If you're wrong, someone else will correct or modify your statement. See Wikitravel:Be fair for more details on stating opinions.
Some exceptions to this rule should be obvious, but are listed here for completeness.