Well done version, dino notwithstanding Well acted and truer to the book than most versions, this film keeps you interested as long as you are not concerned about the dinos. John Rys Davies and Warner are very good as usual. The rest of the cast are virtual unknowns even today, so you are not seeing seminal performances by current well known actors.
As far as the dinos, think Dr. Who back in the Jon Pertwee era. Some scenes aren't bad but generally we're talking rubber dinos that look like rubber dinos. As in Who, the story outweighs the special effects. (Current Who TV has great special effects of course.) still, as I said, some scenes are better than others.
Notwithstanding them, the film is worth a look.