I've been looking to upgrade my chiller for some time now and have visited quite a few manufacturers' websites to see product descriptions. In comparing different chillers, I notice that there's a huge discrepancy in some of the ranges of cooling for products of the same HP. For instance, a 1/4hp ViaAqua cc25 claims 10º pulldown in an 80 gallon tank while a PCI 1/4hp cl-650 claims a 10º pulldown for a 180 gallon tank. Of course other issues like ambient temperature are a factor, but are the descriptions worth reading or should I just go by the horsepower (which is proportional to BTU/unit time)? Any thoughts? btw, the tank on which i'm looking to install a new chiller is 120 gallons. The price difference is around $200 between these chillers. Justifiable?