Yes, that is one thing that is broken about diplomacy in the game, and Super-Diplomat definitely enhances it!  I also like Breeder and Hive a lot.

Someone pointed out to me that with the new extreme-planet slider in 2.0, Super-Adapter would be exceedingly useful.

Sentient species taste better...

that's the one thing where AI isn't powerful

it is not able to see things far away enough to define a policy about things to trade or not and ajust values in consequence

I think that for each world you buy the value of the next should be higher unless its in their interest to sell you this specific planet

I don't want to completely rule out a diplo victory( or simply buying worlds) but still the AI is too easily abused it seems...

in fact I'm thinking about a partial "fix" to this that would be to give small diplo bonuses (like 2%) on each and every available tech

that would mean that the more knowledge an empire has about its surroundings and the workings of it, the more it values its own belongings

which would make sense and would make AI that don't research diplo techs have a higher diplomacy rating

the only problem is :I don't know how diplo works internaly so I'm not sure that would really up the difficulty of trades

hum.. given my own experience (although very partial)  I wonder if it's simply not the opinion they have of you

I didn't try out the diplo super ability but the races with which I am "neutral" don't seem to want to speak to me as often as races with which I am "close"

so I ask you the question : doesn't they have better relations with you (because you have a higher diplo and/or diplo superability) ?

Six turns instead of the usual twelve, I belive. I could be wrong on the numbers, but I'm pretty sure it cuts the wait time in half.