I think the most significant thing in this situation is that we have a history of making Deere hardware do things that even Deere is not always able to do, and we are typically earlier to release that functionality than are other "third-party" software companies.   Beyond that, for precision ag purposes, SMS, MapShots, and FarmWorks look to be fairly similar to me.   Just as we probably have an edge on working with Deere stuff, AgLeader most certainly always has an edge working with their own hardware.   

And, I cannot speak to SMS's ability to do "conventional" recordkeeping.   I do not know if there is a way to record that you planted a field (or part of a field) to specific variety w/o having an actual as-applied log.   If that feature isn't available now, I would guess (and it is purely a guess) that it will be there before long, as a function of the release of SMS mobile.    Farmworks X2 and our EASi Suite do support full crop recordkeeping.

Summary, if you don't find some compelling "gotta have" feature in SMS (and there are many nice features), then if you want good GS1/GS2 integration, I would be comfortable recommending EASi Suite to you.