I bought my capcell a few years ago and it still works fine and looks cool. Honestly though dont be a cheapskate, the 400 is for lightwieght low power systems. It will make a difference regardless but you should really consider your power specs.
I have one Crunch DRA2400, one Hifonics HFI1500D in a carolla pushing two 12" American Bass XD's, Two Kenwood 6x9's and a set of Kenwood 6 3/4 components. Guess what my lights still throb to the beat! Not because it's bad but because it isnt matched up properly, so consider how much amperage you alternator put out in the first place. Mine is about 65 amps.
Then take into account any future upgrades, if all you want is one amp to run a set of subs your at cap cell 600 minimum, multiple amps puts you in capcel 1000 territory. Spend the money the first time out and you wont be disapointed. Leave the 400 for systems running 200 watts rms and under.