If the Seb is a Regular one 2007-8 or earlier I would take the Seb, since they are no longer in production, and if it's BG-42 or ATS it's worth even more.
You can't go wrong with a Sebenza, I've put my Small Sebenza up against every knife that i've seen, held or owned over the last year or two and I havn't found a single knife that has even come close to the quality, crafstmenship of the Sebenza.
And on the s30v being brittle, it must of had a bad heat treat on it, every s30v sebenza that i've used never had a problem with chipping, the edge would roll under very hard use, but by putting a micro bevel on it, i've never had the problem since, the razor sharp edge wears off but it still has a good working edge for a long time after that.