I recently purchased a stump bucket for my NS6010. If you use common sense (i.e. don't slam your machine into tree stumps trying to knock them over), this is nice to have tool. It will not replace a backhoe for trenching, but even if you were to buy a backhoe, I would say it makes more sense to rent an excavator for a large trenching job.
There's amply videos on-line on how to use them in a proper way.
Since this is just welded steel and not high-end technology I went with the Titan large bucket. Deals can be had if you wait for their sale.