Yes. The Trustfire and many others that have two ports are 500mA chargers, but they are regulated to 250mA per side. This means that they will take about 8 hours to charge a 2000 mAh battery. The Nitecore chargers are 500 mA per side chargers, what is classified as a "fast" charger. They will charge approximately twice as fast. If you have a look the output rating of the chargers you'll see that the Trustfire is 500 mA while the i2 is 1 amp. This is the total, not the per-battery charge rate because each side is regulated. The i4 will of course have a total output rating of 2 amps, hence the much greater cost.
While 500 mA is still a safe (ish) rating for lithium batteries, you may find the batteries getting a little warm. This can affect the efficiency of the charge, and also the long term health of the batteries. I've just bought two extra batteries to have some extras in rotation so that I can always have at least one charged and ready to go, as I prefer to charge at the lower rating and keep the batteries cool while doing so. The long charge times are bit painful however; I don't blame anybody for taking the fast charge option.
Batteries are fairly cheap, maybe get some extras rather than a faster charger? This gives you some extra redundancy as well.