Like MarkV said the backblading issue is the only change you will need to make. Use the back of the bucket instead of the front for smoothing. The toothbar has saved so much time for me.

In addition to more aggressive digging you also gain the advantage of now having a very large rake for spreading material. I use the toothbar as a rake after dumping enough soil on a particular location. I tilt the bucket forward enough that the teeth will protrude a few inches lower then the solid bucket edge. I then backdrag the bucket with the FEL virtually lifting the front wheels off the ground. This distributes any large pieces/lumps of material "raking" them out. Next I tilt the bucket up so the teeth are only protruding a couple inches and backdrag again, many times in a different direction. Tilt the bucket almost level and drag again. The next pass I can usually tilt the bucket up and use the back edge on a couple passes to smooth out the material to a nice finish.

Learning this technique took much less work and practice to become proficient then learning "box blading". Maybe everyone else already knew this but I had never heard it discussed here before.

You also asked <font color=blue>Can you still effectively "scoop" gravel or fill dirt ?</font color=blue> Yes, as a matter of fact you will need more rear ballast because you can scoop and hold more in your bucket.

The teeth on the toothbar can also be hooked through the handles on trash cans when hauling them to the street (have a quarter mile driveway).

Biggest drawback to the toothbar is it makes the FEL that much more of a possible weapon. Afraid that someday I may accidentally ram the teeth through the side of a car or ...

Toothbar for my NH 17LA loader with 72" HD bucket was around $350.

Implement usefulness in order: FEL, toothbar, box blade.