I think its worth a watch, I have my own reservations but since it predates Arnie and his gun totting mercs, its okay.
Assuming that the Predator in 1700s isn't the same as the one Arnie uses that would make sense because I find it odd that in a few hundred years the species would evolve this much.
Predators physiology changes so much, from the fangs on his face to the shape of his face and other features on his face such as the skin on his face and overall physique that it makes me wonder if they're even bothered by with the thought of trying to be as canon as possible and retain his features and agility.
Otherwise, if you don't bother yourself with comparisons its actually a pretty decent one to watch, i'd recommend that you go and watch it and have a look for yourself.