Well, they only explode when their resistance is exceeded, and their resistance is 500% that of a battlesuit plate. Considering that a normal battlesuit has five plates... any kinetic shot that could break a fragplate forcefield could probably kill a battlesuit, or severely damage it. Plus, forcefields are very resistant to the standard BS-killer weapons; Plasma just 'hits and stops'*, while PSL shards rely more on a very thin contact point rather than raw kinetic energy--IIRC, they actually have less kinetic energy behind them than a gauss cannon.
We do have the assaultsuit armors, but the problem with those is that they're good against one or the other weapon type, but weak to even small arms of the wrong type. Also, forcefields are actually better than hexbug in kinetic resistance if they don't cost more than twice as much. A 1" hexbug layer, IIRC, is damaged at 200% gauss cannon power, although it does stop the round. When you account for the fact that a forcefield can't be taken out with a measly laser rifle, it clearly outclasses hexbug. The same for hexsand, since even weak forcefields don't seem to care much about plasma or lasers, and won't break to a gauss rifle.
AND this isn't even accounting for the fact forcefields don't take permanent damage unless destroyed. So, you can be hit with a hundred gauss cannon shots, as long as they hit different sections of the field, or if you have a short period of rest between them.
And forcefields are a quarter inch thick (or less if you really need it), which is vastly thinner than even our best armor, meaning that pretty much anything can be armored... and it's probably massively lighter than any remotely comparable armor, so our battlesuits can flit around like MK.III troopers... and the standard UWM armory doesn't even employ any weapons which can one-shot a forcefield, aside from the LESHO (which is dodgeable), nukes (which would make a massive explosion regardless, natch) and the fission instigator (...).
And despite all that I'm still planning on only giving HRBs forcefields. The robots who're intended to not be shot at by anything that costs ten or more tokens. Primarily because I know I am highly vulnerable to hubris.
...Ahem, uh, yes, the wiki is mostly up-to-date on the forcefields, except for the last update on them. And no, it's not nice information laid out in descriptive articles, it's just a few numbered links at the bottom of the Hephaestus page. I promise I'll overhaul the Heph research page. Eventually.
*Oh god I only specified plasma shots, not plasma projector shots. Forcefields might break to lavalamp cannons because they use magnetic propulsion D: