Yeah, I think it is, even if you watch only season 1. I don't think you need to be familiar with the Slenderman Mythos to enjoy them, either. I hardly knew much about it when I started. There are a couple of elements to it that seem ridiculous, but aside from a few moments of cursing over someone filming the ground too much in some entries and the overly cryptic nature of a lot of the messages, I think it's still very well done for the suspense and raw horror factor.
The first few entries are very short and do a fantastic job of setting the tone of the series, so I think it's worth it to at least watch up through entry 12 or so.
--
Essy, Avian Enthusiast