Bill's right on the money.
Slower to cut by about 25-30% (removing .035/.025X material), more tension to get it to cut properly, more load on bearings, crack more readily (doesn't like the smaller radius), though that's all pretty small beer.
Biggest drawback I'd say is having to reset the blade-to-guideroller gap each time to get it to cut square vertically down.??
I can't think where a wider kerf will be that valuable, better to have different TPI blade in .025, than an extra in .035
If you really think its worth it, I certainly wouldn't get it in Bimetal, Flexback would do as well in most metals and be more flexible as well, reducing those loads etc? - jv