In the original, you were in a small area, as he slowly walked around shooting at you...it was pretty poor tbh.
Now, the area is much, much larger. I am not sure of all of the tactics you can now use, but I ended up crawling through a few vents to get in to secret rooms, in order to hack terminals to open up doors to new areas, then I hacked one terminal to control turrets, but as I did not have the strength enhancement, I could not move them to place them where they could do damage(they are in a small room), so I had to lure Barret in to room, and let them take care of him. Barret still has to be killed of course, so that the cutscene remains the same. Tbh, it was a lot of effort when it probably would have been easier to just kill him myself
Also, there are some security cameras in the room which can spot you and tell Barret where you are, not sure if they were in before?
All in all, much improved....if you are rubbish at combat, it works out pretty well, but if you are slightly proficient with any upgraded weapon, it is probably less hassle to just kill him yourself tbh