The best choice depends a lot on the quality and reliability of your home service. It also depends on what else you have in your house that can cause surges. Electric motors in furnaces, washer and dryers, refrigerators, etc., produce electrical "spikes" on your home AC. They also produce what's called reverse or back EMF. These are bursts of energy that happen when magnetic fields collapse around coils. It's these types of surges that are most common in homes and not those from the outside. If you have a lot of other electrical appliances with such motors, you should consider better protection. I can't give you numbers in joules or whether or not manufacturer ratings are realistic. The other thing you need is protection from those quick drops in power that cause your PC to turn off. These are the ones where your lights flash off and back on withing a second or two. In other words, run time probably isn't all that important. More run time just allows a person to properly shut down their PC or let the software do that for them.
Personally, I've always liked APC products but that's just a matter of choice and I've no experience with the brand you mentioned. I really don't care that much about added features or what information an LCD display can provide. They're nice but not necessary. So to make a short story too long, I'd advise you to consider how sturdy and stable your home power is and how often you see flickering lights or hear motors slow down when you turn things on and off. If you suspect your power is "dirty" get something better. If you feel it's fairly clean, you can probably get by with something that's just adequate.
Hi, I bought a Cyberpower CP825LCD UPS locally, new for $90 + tax. It has a LCD display, and software that shows more than the LCD which is limited. I fould out the power factor of this unit is only .54, and the industry standard seems to be .6. I see that with what I have hooked up, I'm pulling between 130 at 157 watts, and don't plan on adding more. Now that I know that, I'm thinking I should have bought the CP550/330, which does give a .6 power factor, and is only $40 (on sale but reg. price is only $45). Both units have phone line protection, and desktop software, but the 550/330 has no LCD which is fime with me. The 825/450 protects 1030 joules, and the 55/330 = 890 juoles. I assume I should take the more pricey unit back and get the lower cost one, which allows almost 75% of the wattage. Does this sound right? Both have simulated sine waves, fine with that as well. I just don't see the big reason for more than double the price. Thanks much.

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