As a veteran GM of Deathwatch, I know from personal experience that Force Fields make everyone's life miserable. They're pretty much a no-brainer piece of equipment - you almost need to have one. They're just too good. They go into effect every time you're hit by an attack, they completely negate the damage from the attack, and the chance of getting an Overload is laughably small on models with decent craftsmanship (to say nothing of models that don't Overload at all....). As a GM in Deathwatch, it became necessary for every one of my bosses to have one just so it could survive more than one round of combat. Now, in Black Crusade, my players have just stepped off the Chains of Judgment (from the Broken Chains adventure) and are browsing the markets of Q'Sal. It's only a matter of time before someone thinks to roll for a Force Field Acquisition, and with four players, odds are high that at least one of them will get one.
As GM, I see three options.
1) Do nothing. If my players get a Force Field, so be it.
Not really an ideal option.
2) GM handwave - it's fresh out of stock, unavailable, emitting harmful radiation, etc.
Heavy-handed and leaves a bad taste in my mouth.
3) Either place restrictions on Force Fields or re-design them.
This seems to be the best option to me, but I worry that my players will see this, too, as heavy-handed (ignoring the fact that any house-rules will apply to enemies as well...). Some thoughts that I had on this included setting an Infamy requirement to make the fields available, making certain weapons bypass Force Fields, simultaneously increasing the field's chance to go off while increasing the Overload chance, giving Force Fields a power source that must be recharged, or creating drawbacks to using Force Fields (maybe they emit radiation?)
What are your thoughts?