This may not be as huge an overhaul as many people would like, but it's a simple-to-implement improvement (nerf) to have jam duration = jam strength / sensor strength x 20. This would dramatically nerf ECM drones, off-spec jams, as well as lucky jams on high-strength targets. It is also an enormous buff to ECCM, sensor integrity links, and the sensor strength implants. Any ship with sensor strength of 40 or 50 points would turn even very high-strength specialized jams in to more of a lock-break effect.
This does end up being a slight duration buff to perma-jams when there is a greater than 100% jam chance on the target, but that is mostly irrelevant since the perma-jammed target is pretty fucked anyway.
EC-300 on a Vagabond = 1.4 second jam duration
EC-300 on a Megathron = 0.95 second duration
EC-600 on an Enyo = 2.7 second jam duration
Basically, fuck ECM drones.
Falcon(13.4 strength jams) Minmatar jammer on a Vagabond = 19 second duration [basically no change, i.e. you are totally fucked anyway]
Falcon off-spec jammer on a Vagabond = 6.4 second duration
Falcon Gallente jammer on an Enyo = 24.3 duration [mostly irrelevant as it's already a 100% chance to perma-jam]
Falcon off-spec jam on an Enyo = 8.1 duration
Falcon Gallente jammer on a Megathron = 12.7 second duration
Falcon off-spec jam on a Mega = 4.2 second duration
Falcon Gallente jammer on a Mega w/ an ECCM = 6.5 second duration (5.7 if overheated)
Falcon Gallente jammer on a Mega w/ 2x ECCM = 3.54 second duration
Falcon Amarr jammer on an ECCM Guardian = 7.2 second duration