I have not run a #2 type of grapple, so here are my thoughts. Most of my experience is with the grapple on a 2k lift skid steer so lift capacity was not as much as an issue as with compacts. I loaded lots of scrap, brush, and manure with #1 brush grapples.
I have never had a problem grabbing brush with a #1 type of grapple out of a pile, or from the ground. I normally load from the base of a pile with the bottom of the grapple running close to the ground.
With a #2 grapple you must have a good grasp on the load as the clamping action is what is holding most the load. A #1 grapple you have a shelf it sits on and the clamping action is more of a stabilizing force. Both have the same clamping strength for equivalent buckets, however A #2 relies almost solely on clamping to keep load in place, where as a #1 carries the load with the bucket and just holds it in place with the grapple lid.
I have never had problems getting logs, or anything else out of a pile with a #1. Look at all the lumber mills they use pallet forks with a clamp on them. Also if the load is heavy you can tilt the grapple all the way down and grab the log with it slightly under the pivot pins. This will actually put the load closer to the pivot pins than a #2. When you do this a good grasp is critical as it is with a #2, unless you can get the lid tines all the way around the log to support the weight.
A #1 grapple can carry a greater volume of brush because of the curved tines and floor. However if your just carrying just a little brush then a #2 will do it better, as the #1 will be unable to clamp on a small load. A #1 works best if you can fill it mostly full. Look at the gap between a closed lid and the rest of the grapple, you minimum load for the grapple to be effective will be about this size.
An equivalently construction #1 will weigh more than a #2 due to the larger lid, and floor.
Both suck as rakes, Most #2 have a bar just a few inches above the bottom, only allowing a slight raking action, about the same as you can get with a #1 tilted forward. However a #2 will be easier on the loader to rake with as the bucket cylinders are mostly retracted during raking, reducing potential for damage. #1 with a completely flat floor will act as a better rake than #1 with curved tips on the end of the floor.
You can carry multiple awkwardly shaped objects like rocks in a #1, whereas with a #2 you will be limited to similarly sized rocks, and that will still be a challenge due to rocks being slippery and heavy. When it comes to rock picking time you only see #1 grapples in the field.
If I had a subcompact tractor I would buy a #2 as the weight savings would be a critical factor for me. However if you have the lift capacity I think a #1 with dual lids is better. I have run a single lid and it works fine, however there were a few times that a dual lid would work have worked better, however not any time I can think of when a single lid was better.
Playing with brush with a tractor is asking for trouble. Oosik makes a great point here;
