I would think that a sweatshirt would be better or perhaps both. I would think that most of us live in climates that are not exactly t-shirt weather during the holiday season. Even here in NC, we can get some COLD days during setup time. Last year was very warm and was t-shirt weather but the year before, we had daytime temps in the low 30's andd at night in the 20's, neither of which were t-shirt weather.
Of course, as fun as it tis to talk about, until we get permission form RJ (it is his logo and name), nothing can happen either way.