I just saw a cut of this, ask me anything.
Stallone is doing a great job but the director is lacking punch. The third act is violent and fun but the film takes a long time to build up momentum and the hard core climax is quickly over.
I love Rambo 4, both cuts, but Rambo: Last Blood feels like a completely different film. Hopefully we will get a longer "Stallone" edit when its released digital.
I cant disclose where and when I saw it as I have signed a waiver.