I definetly think you should take time off once in a while: no tapering should be done what so ever. Even though it might be benefitial for the muscles, I think the joints really deserve some rest, and taking a week of will not make you lose any muscle or strength, assuming that you are healthy and eat right. I say this from an anecdotal standpoint, since I've done it several times, due to exhaustion, scheduling issues and other things. If you are sick however, a cold might make you a bit weaker (but not visually smaller), and a flu will destroy you.