Seed4ME is great if your Xbox is already banned off of live (or if you don't give a hoot about live).
Otherwise, I'd stay away from it. Review copies could be encoded with code that differs from retail releases. This is quite prominent in the movie industry.
Notice how they sometimes catch the people that leak movies early (In America, at least)? It could be an extra injected pixel of pink at frame 23333 that would be a dead giveaway of where it came from. They, Microsoft and it's 3rd party devs/pubs, could work together and find all the Xbox 360s that have this game on it (be it through achievements or saved games) and that's it, banned.
I WILL, however, pre-download the files and hope that the retail is identical to the review (ss and all that). In which case, I will then eat my wordst.
tword eating is based on a release by release bases. Any words eaten shall not be reimbursed. Offer not valid in Quebec.