To be honest, I don't care that much about what Donald X. says about rebuild. He didn't playtest it enough before the deadline? Well, that makes we wonder why in hell he should have deeply playtested any variant of rebuild after the redactional deadline. Sure, he knows more about Dominion than most of us do - but then again, he doesn't know everything.
My opinion about Rebuild is that the best possible variant is the card we have right now.
The biggest downside is that it vastly reduces strategic decisions, and so, luck gets more important. So far, so true - but is that really such a big problem? I mean, if we don't want to have luck involved, we should play chess. In my opinion, the most important problem with luck is that you don't have to waste too much time in a situation you didn't deserve. But this usually never happens with rebuild, as it leads to very fast games. You might get knocked out by a player 15 levels below, who plays straight turbo rebuild, but probably the only consequence will be, that two minutes of your dominion life might be slightly boring. (Sure, your rating will drop right now, but in the long run, every player will get the same portion of luck).
This is maybe what I like most about the actual version of rebuild: The number of interesting decisions per minute you have to make is pretty high. Most of them are rather tactical than strategical, but that accentuates the amazing variety dominion games can have.
If I play against a player 10 Levels weaker than me, I prefer to have a rebuild battle than a scryingPool-Hamlet-Storeroom-Board.
With rebuild, I might lose 40%, but there will probably some interesting tactical moments, and 4 minutes later, I can play a new board.
With the mentioned engine, I might lose only 30%, but the risk to watch (or play) a boring engine with tons of simple decisions, ending after half an hour, is much higher.
tl;dr: A slightly more luck-based card leading to a simpler, but fast game, with some tricky decisions left, is an interesting diversification, not a problem.