I liked it as well. Was it perfect? No. But then, as I've often said, no show (or film) is. What I have seen I've enjoyed.
As far as reviews go, I've now seen slightly more favorable than unfavorable. Variety and Entertainment Weekly really liked it. TV Guide and Zap2it did not. And on the PBS review show Just Seen It, which uses three critics in its reviews, one reviewer literally hated it, while the other two really liked it. Apparently the show is one of those that you either love or hate with little middle ground.
Of course, purist reviewers have had problems with the changes. One thing I've most often seen cited in the unfavorable reviews is making Van Helsing Dracula's ally rather than his main protagonist. But making changes like that can actually freshen things because they're not what's expected. I suppose it does remain to be seen how things in that relationship play out, but at this point I think having Van Helsing revive/release Dracula is a great new twist.
Also, reviewers have complained that the show isn't violent or sexy enough. Though the mere fact that some are complaining on those fronts is interesting in and of itself because this take on Dracula isn't on cable, it's on network TV, where there are much stricter standards against violence and sex. That being said, though, apparently the quotient of both will be ratcheted up in future eps because Variety says the "series pushes boundaries in terms of gore, torture and sex."