There have been some positive posts here about Travel Guard. However, there have also been some nightmarish tales here involving several insurance providers, generally relating to a misunderstanding or difference of opinion over what types of situations are covered by the policy.
I believe everything depends on why you are canceling. To be covered, you must cancel for a "covered reason", as explained in the policy.
As examples, if an immediate family member died a few days before your trip, sending a copy of the death certificate along with your claim should bring an immediate payment. In the middle, illness accompanied by a letter from a doctor stating that you can't travel, would likely mean Travel Guard would investigate. At the bottom, canceling because of loss of employment or because a boss said you can't take your scheduled vacation would mean no reimbursement, because those are examples of non-covered reasons for cancellation under the Travel Guard policy.