Having worked at a very large snapper dealer never heard of the problem with the 33" blade vibration, If the 33" one will get where you need it to it is the best choice, the longer the blade the higher the blade tip speed which is giving you better suction for lifting the garss and giving you a good cut and more force throwing the clippings up the chute to reduce clogging, just keep an eye on the blade and add on lift kits for it to make sure they are not worn on the back which will cut down on the suction. Actully now that I think about it there was some problems with the 33" ninja mulching blade if cutting tall wet grass which a mulching mower shouldn't be doing anyway.