I agree with most of what's been written by other reviewers, so am giving it four stars. Now for that "but" in my title: Where in the book does Fagin come in as a conjuror -- not to say clownish? My reading of his character is that he was exploitative, fawning and self-serving. The scene devoted to his sojourn in prison is also over-long, and could have been considerably curtailed. I also don't remember him being of Czech descent.
The background to Oliver's birth in an orphanage is also over-long, but it does make for interesting viewing, as well as filling in many gaps. It's not Dickens, but serves the story quite well. There are also too many unnecessary appearances and re-appearances by the "first" Mrs Leeford (excellently played by Lindsay Duncan) as well as Oliver's half-brother, aka Monks. But I cavil!
Overall, casting and acting is superb: my Oscar would undoubtedly go to Andy Serkis for his Bill Sikes. (Just as an aside, for me nothing could ever compare with the brooding menace of the late Oliver Reed in that role when that awful musical travesty was made.) Sam Smith also rises magnificently to the title role. Marc Warren is quite frightening as Monks. In fact, there are really too many fine characterisations to single out any.
Story line: Apart from my quibble that the footage devoted to Oliver's heritage and birth is unnecessarily long, the script is, by and large, faithful to Dickens' classic. A few deviations need not spoil it for the purists. And this is definitely a fine production when placed alongside the plethora of Junk produced by the cinematic moguls of late. I'm glad I bought it and hope you will be, too.