I use spikes when I top trees -- before y'all pile on, I'll explain.
There is a California Five-spined Ips bark beetle outbreak going on in my area. This beetle starts in the top, sometimes just in a few limbs, half the live crown, or the who;e tree, except that lower trunk over 18 in. diameter is usually green or attacked by western pine beetle.
For those clients that want to save a large ponderosa pine, I have removed from 15 ft. to 40 ft. of top, followed by climbing the tree again with a backpack sprayer and applying an insecticide to the top-most 20 -30 ft. of trunk and out on the limbs to about 2 in. diameter. One 3 1/2 ft. diameter pine is still alive after I removed 40 ft. of top and sprayed it with dinotefuran in September 2012. This tree had about 30% of crown volume removed; most of the rest had less than 25% crown volume removed
The 12 trees or so I have treated in this way between September 2012 and September 2013 have all survived. This bark beetle has three generations per year between April and September, so all the trees were "tested" by bark beetles except for the last few. In the off season for bark beetles, In Fall 2013 I started injecting trees at the base with the ArborJet system and product, combining ememectin benzoate and propiconazole; looking forward to how these do in 2014. Most were uninfested, but some were infested (and had the infested portion pruned out).
Why spikes? Removing 20 - 40 ft. of tree is safer to do with them on, and the top is DEAD. Plus, I rig a top rope from the ground, pull up my life line passed through a 'biner on the end of it, tie of the top rope, and then walk up the tree with a flip line; there is almost no weight on the spikes, and they usually don't penetrate at all, or just in the outer inch of loose dead bark. The point is not to trash the live crown; spiking the live portion of trunk would just attract bark beetles and possibly spread the blue-stain fungus brought in by the bark beetles.
I agree that topping is bad in the way it used to be done in perfectly healthy trees of all species, usually for the view or because the tree was "too tall"; hence the ban in the A-300 standards. IMHO, the decision to keep top-killed pines in a bark beetle epidemic is a special case that is not covered by the A-300 standards. Also, it just so happens that p-pine puts out a lot of resin that seals up the wound and soaks the underlying wood, making decay less likely than in other trees. For example, we have all seen grey birch rot out from heading cuts only 2-3 inches in diameter. Not all ponderosa pines with top-kill are candidates for this treatment -- just ones highly valued for framing the view or screening. I also inform the client that the tree will need follow-up inspections and pruning in the future, as well as insecticide applied to the remaining top if the tree is topped during the bark beetle flight season. I would never top a large healthy tree.