There are two things wrong with this movie IMO:
1. It's displayed as a real event (and it is) but Stallone put too much comic book violence/action hero adventures in it for such a horrific real life event. It was like it profited off of other peoples tragedy. The thing that would have made it go over a little better with me is cut out the very first part with the real life news casts. Just put up a little prompt at the beginning explaining whats going on in Burma instead of showing what actual people go through and try to put a fictional action hero in the middle of it all.
2. It was really disturbing to show little kids be mutilated in the village. Once again, this is a fictional 'guy movie.' Putting children under a soldiers knife or in front of an AK-47 is just too much to divulge when I'm trying to enjoy the other pieces of bloody glory.
Besides those two things, I still gave the movie a 10/10. It was great fun, but those two small tweaks would have given me more leeway into entering this world where one soldier lays waste to genocidal maniacs.
On a side note, though. It would be interesting to see a complete remake of the original First Blood. Make it more connected with the book, but update it to today. Instead of having Rambo as a Vietnam vet, let him be a Iraqi vet. Teasle, instead of a Korean War vet, a Gulf War vet. This would allow them to be somewhat closer in relation to one another due to their common former battlegrounds. Also, don't change the ending of the book. Rambo dies!