Forget the film, riveting as it is, but watch the 'commentary' (a DVD extra). Stallone's comments about the background and making of this film are so informative you'll want to watch it time and again.

I was always gonna like this movie on the account of being a massive Stallone and Rambo fan.
The film is well made, tight 90 min running time and a good story, relevant to what is actually going on in Burma.
Be warned the film is very Gory and Violent in parts. Much more than the previous 3 in the series.
Performance wise, well Stallone is RAMBO, even though he is a little subdued and beaten down with time and age this time.
The last scene was brilliant - bring on Number 5.
If you are already a RAMBO fan then it is a 4/5. And if you are new in class then probably a 3/5.
P.S - check out the extras bit with the little doc-u about the Burma situation. Interesting

I'm a fan of the Rambo series, esp First Blood, which I can watch over and over.
This film is quite shocking compared to the others in the series. The much-touted death count seems on the low side for one thing. But it's the graphic nature of the killings which is so disturbing. There's bits of people being blown or hacked off with oceans of Harlequins-inspired blood filling the screen. It's pretty unpleasant, almost heading into Private Ryan territory. I get that showing the horror being inflicted on the people of Burma is the main point of the film, but I don't get a thrill from watching Rambo scythe people literally in two with a machine gun. It's just too over the top and isn't necessary for the pretty limited story. It detracts from the brutality of the regime and the plight of the people.