are these changes that can be tweaked as bitshares evolves, like bitcoin fees are tweaked, or are they more or less permanent to the XT chain?
How to make changes, and what changes to allow, THAT is the critically important question. Any DAC that can more intelligently make drastic rapid changes like this will always blow away all dumb hard to change competitors.
The Bitcoin foundation has quite a laborious, slow and involved process to propose, vet, and get these kinds of changes accepted into the network. And even with all that, there is a chance that some miners will not accept any particular updates/changes, possibly resulting in a forked block chain. Obviously, such would be devastating to any community using the coin.
That is why having the ability to build and measure how much consensus you have is so critically important. Getting a network of machines to achieve a consensus on what blocks to accept is one thing, getting all the people rapidly on board and educated (i.e. amplifying the wisdom of the crowd) for dramatic intelligent changes to how the network consensus is achieved, is an entirely different and far more important issue.
Any smart DAC, that can rapidly measure and build consensus amongst the crowd of coin holders and miners, way more effectively and intelligent than the Bitcoin Foundation will always blow away any DAC that is fixed, or very difficult to change/improve, like Bitcoin.
The consensus building system at Canonizer.com is all about exactly that. Amplifying and educating the wisdom of the crowd, building and rigorously measuring for the amount of consensus there or isn't, what is required to get to the level of consensus required, as rapidly as possible, all in a leaderless way bottom up way, and so on. Our goal is to make Canon Coin just such a 'smart' currency, able to change and adapt far more rapidly than any other currency, in a leaderless amplification of the wisdom of the crowd way.