First, let me say that I've been buying Tripp Lite products for nearly 20 years, in fact I have another LC-1800 that I bought new in 1995 - 17 years ago. Though the model number was the same, the design was very different then.
The problem with any sort of power protection device is that unless you have the right equipment to measure what it actually does, and you have the time to perform such tests, you don't REALLY know how well protected you are. Many people sing the praises of this or that line conditioner, this or that UPS, etc. - but until something happens with their power, they don't really know.
Having said that, I recently bought a very high end HDTV and was interested in protecting it mostly from brownouts that we sometimes have here, usually during severe storm season (U.S. Midwest). The candidates for this included the LC-1800 and an APC UPS (model BR1500G). There were other candidates but I'll leave those out since I dropped them off the list for completely unrelated reasons, and never did test them.
Before buying anything, I contacted the tech support departments of both Tripp Lite and APC in order to find out how much voltage correction these units were capable of providing. Frankly the contact with Tripp Lite was what I had come to expect: a human being, speaking English, based in the U.S., and willing to at least try to answer every question I had. The contact with APC turned out to be an e-mail from India, and it took two tries before any meaningful information came forth from them.
So the LC-1800 and the APC UPS both arrived. I do want to say that my test results are based on the assumption that I did not get a defective unit. It's always possible that mine was defective, but I'm not interested in spending any more time messing with this.
Tripp Lite had told me that during a brownout condition, the LC-1800 should boost output voltage up to nearly 120V if input dropped to as low as around 90V. MOST IMPORTANTLY, they said that if input voltage dropped to the point where the unit couldn't boost the voltage back to useable levels, it would instantly and cleanly shut off output completely, so as to not subject the connected equipment to a severe undervoltage condition.
I connected the LC-1800 to a variac, a device which allows you to control the amount of AC voltage supplied. I used a Fluke DVM to monitor the voltage supplied by the variac, so that I could be sure of the points at which the LC-1800's behavior changed. I'll point out that in one of my calls with Tripp Lite, they suggested that I use a variac if I wanted to be certain about the unit's performance.
Starting at 120V from the variac and slowly dropping the voltage, the LC-1800 reported the line voltage as "Low" when the voltage dropped to 113V, and it boosted the output from the LC-1800 to 123V. Very nice. It reported the line voltage as "Very low" when the voltage got down to 103V, and output from the LC-1800 remained at 122V. Again, this is just what I'd expect.
The problem lies in the fact that as line voltage continued to drop (as it easily could during a brownout), the LC-1800 NEVER DID SHUT OFF THE OUTPUT. As line voltage dropped to 50V, the LC-1800 was still outputting 60V. As I continued to drop the line voltage, the output from the LC-1800 simply continued to drop, all the way down to less than 10V. That was all I needed to see on the LC-1800 and it's in the process of being returned.
I went through the same process with the APC UPS. It's not a magic bullet either; its automatic voltage regulation function (similar, at least in concept, to what the LC-1800 uses) will allow the connected equipment to see voltage as low as about 100V during a brownout, and as high as 128V during an overvoltage condition, before it switches to battery - which then provides 115V for as long as the battery can hold out. The difference is, it HAS a battery to switch to, and doesn't attempt to keep boosting (or trimming) voltage no matter how low (or high) the line voltage goes.
Don't get me wrong - a line conditioner and a UPS are two completely different animals intended for different applications. The reason I'm comparing them is that they both provide (and their advertising makes a big point of) automatic voltage regulation in order to protect connected equipment from undervoltages and overvoltages. My new TV doesn't "need" to stay on during a storm, therefore I have no need for a UPS per se - but I do want it protected from wild variations in voltage, and it seems that in order to get this, I need the additional functionality of a UPS. You might need it too, if you're considering the purchase of a line conditioner.
I'm laying out the data here so that you can make a more informed decision. I may buy another LC-1800 in the future, but it won't be to protect anything from brownouts. If you aren't concerned with brownouts, and only want to stabilize your line voltage which is already assumed to be within a reasonable range, the LC-1800 can do a fine job. But, the one I received does not perform as Tripp Lite's tech support department said it would, and it's a LONG way from performing to the level implied by their advertising in my opinion.