Agreed. The film could be average, it could be good, who knows. But there's no way it can be worse than the prequels.
I love the practical effects. That's the type of "fan service" I can cosign. The beauty of films like Alien, Star Wars, etc was the sense of wonder and amazement at the...well, art. Even as a kid I'd watch the documentaries and behind-the-scenes for those films, and it really opened my mind creatively and was part of the reason I got into drawing, arts and crafts, etc. Whereas nearly everything in the prequels and most films today is CGI. Yes creating stuff on a computer is interesting, but it's also a studio crutch to me. Time and money wise it's basically a studio throwing some dough at an (underpaid) company to create something that almost never looks that much different or better from the hundreds of other CGI filled films that come out each year.
This Star Wars looks fresh. Those behind the scenes pics look beautiful, the trailer was great, etc. Even if it's not a good film it's going to be great seeing a well crafted world brought to life.