I do the opposite. I don't use hard mode, but I do use the reputation system.
Rudel made a post about hard trading that I agree with. It was something along the lines of it being
a feature to hide bad AI. I haven't played with it so my opinion shouldn't be given that much weight, but from just reading about it that's the impression I got too. It's harsh, I know, but it's not the route I would have gone.
In the same thread texasmame also made the point that it's like a pony express mode and I agree with that as well. MathBandit replied that humans don't reply like the AI and while that is true, there is also a wide range of how humans react. Some will offer a well thought deal right away that all you have to do is say yes to, whereas some will just say, "hey, I'd like to trade with you", and others are somewhere inbetween. And if not enabling this mode means not slowing things to a crawl, then I'm not enabling it. Maybe some people like long drawn out trade talks, but I sure don't. If you want me to trade with you, make it easy for me.
In the end, I think it comes down to it's a feature for some and not for others. For people like me who don't trade much or who try not to fleece the AI, there's no point to it. For people who like to trade a lot and who would rather the game put up barriers than ask themselves whether it's a fair trade, then maybe it is for them.
As for the reputation system. I don't know. I like the sound of it and I'm giving it a try, but I'm not sold on it. I mean, I totally get not wanting to listen to any more offers from someone who doesn't complete deals, but when we think of "trading reputation" don't we think of teams, like the Rays, who usually seem to get the best of a trade years down the road?
Rich Grisham of OOTP talked about both in an interview, but which is it? Is it the former like the setting reads in OOTP, or is it the latter like most of us would probably think without reading about it, or is it somehow both? If it's both, that's awfully messy. They should probably be separated. For example, while the Rays might have a rep of winning trades, do the Rays not also make a fair amount of trades? The former would be good for them, bad for us, but the latter would be good for both them and you, no? I could see teams falling in each of the 4 buckets (think of it as a simple 2x2 matrix), but OOTP seems to think it's only a 2 bucket concept.
Where is a GM or team's trading reputation listed anyway? I can't find it. Surely "Reputation" is just the old overall rep. Is it a hidden rating? If so, that's no fun. I want to know whether I and my rivals have good reps or not.