Switching up my gameplay styles allowed me to notice that the AI seems geared to know what approach you prefer. When I adopted a stealth approach, enemies behaved in ways that made it easier for me to deal with them non-lethally. In one room, for example, both enemies had their backs to me every time I entered, but when I used lethal tactics, they were both up and facing me as soon as I came in. It might have just been a quirk of the demo, however - it is a preview build, after all.
Another benefit to constantly failing (besides it being character building, I mean) was that I got to try out different options during conversations. I was delighted how dialog options changed depending on the approach you took. Exploring Sarif HQ, I came upon a couple of employees debating whether or not it was too soon for Adam to return to work, given the extent of the injuries he received during the break-in. The first time this played out, I confronted the guy saying my return was a bad idea, demanding that say it to my face. His reaction and tone were appropriately adversarial, though in subtle ways. He told me "normal people don't heal that fast" which led me to quip that I guess I wasn't normal. He wasn't aggressive, but he also clearly wasn't on my side. The second time, I simply told him I wanted to "set things straight." His tone in this case was much more sympathetic. I'd been through something horrible, he said, and he just didn't want any more funerals. He seemed concerned for my wellbeing, as opposed to concerned for his. It was a small change that won't affect the overall tenor of the game, but rather the role playing experience for me personally.
At the end of the level, you finally confront the leader of the "purists", Zeke Sanders, who has a hostage, so naturally I expected some kind of shootout or maybe a quick time event, but instead got a conversational boss fight. The idea is that Adam, being an ex-SWAT member, has negotiation experience that can help him talk his way through dangerous encounters. You have plenty of options here, but what you want to say personality-wise might not be the best thing to say in order to get the resolution you want. You need to read the other person and determine what the best approach would be; just hammering away on the "good" or "asshole" option more than likely won't work. To make it a bit easier to navigate through the conversation, your dialog choices are displayed exactly as you'll say them, so you won't have those Mass Effect moments where you think you're being charming and end up accidentally insulting someone.