Conservative shields still have some use at least. A normal shield will lose 2% of its capacity every turn/5 seconds, so it will completly run out in 50 turns/4 minutes and 10 seconds. For this reason keeping it on all times is not a very good idea, it would be a hassle to recharge it that often and necessitate carrying a whole lot of batteries.
Capacitor reduces the dissipation rate by 10% + 0,1%*quality, capped at 80% reduction with a 70 quality capacitor. This reduces the drain to only 0.4% per turn/5 seconds, 250 turns/20 minutes and 50 seconds to run out completly. That's a lot better, good enough to leave it on at all times to me. Shield like this would end up having less than half capacity of an efficient shield, but could be used as a permanent protection rather than something you need to activate beforehand. I can recall a few times when I was killed by coil spiders because I walked into one of their webs and couldn't even activate the shield before it was too late. Same for mines.
I think amplifiers would be just fine if they didn't reduce the capacity.
By the way, why is default dissipation rate 10,0%? Shouldn't it be 100%?