Here is a link you might find useful:
TheInverterStore.com - Technical Support
I also called Aims and asked a few questions. Here is what they told me:
Q: What is the efficiency of an inverter?
A: Depends on the load requirement and inverter type. Inverters that do not supply a pure sine wave signal are often low efficiency because the parts of the signal that are not pure sine wave are not used. Some equipment is slightly more efficient using a modified sine wave because the circuitry is simpler. A pure sine wave converter is 90% to 95% efficient. If you apply a load that requires a pure sine wave to a modified sine wave converter, or even worse, a square wave converter, your efficiency can drop to 60% or less.
Comment: For my money a pure sine wave converter is the only way to go. These differences may explain the varying results that people have reported here.
Q: How should you size an inverter for best efficiency?
A: the Inverter will be most efficient at 1/3 the rated load. IE, for a 100 watt load, get a 300 watt inverter, but also make sure that any surge power at start-up is covered.
Q: Is the price of a digital pure sine wave inverter justified over the cost of an analog pure sine wave inverter?
A: in nearly every case, no. Get the analog unit.
Q: Do inverters still draw power when there is no load?
A: Yes. a small drain continues so for energy conservation, the inverter should be switched off when not in use.
One interesting side bar: I have heard people say that Honda generators rated at say 2000W are able to power equipment as large as cheaper generators rated much higher. I've always wondered why, but it turns out that the same principle applies about having a pure signal. You can generate a ton of wattage but if only a portion of the signal is usuable, Then the actual equipment you can run is lower. Hondas produce more usable power because they have a more expensive inverter system which produces a cleaner signal.
I'm not advocating either approach, but I'm going to try the standard electronics on an inverter for my full time AS TV/DVD. I put a meter on my system and it draws 52 watts. At 90% efficiency that is still only 57 watts or about 4 1/2 amps at the battery. It's a 19" Sharp LCD flat screen with a Sony DVD player. My opinion is that for a system that gets used alot like by fulltimers, you may be better off with 115V products. Higher voltage means lower amperage, which means less heat. Heat is a killer for almost everything electric. That's why 115V motors outlast 12 volt
motors, and 220V motors outlast 115V units. For TV units that are used infrequently, the mode of failure is more likely to be moisture, vibration or other things that a 12V mobile ( marine) rated unit might endure better. I'm not so sure this question is purely black or white. More likely it depends on the environment and intended use. Just my thoughts on the matter. Life is an ongoing experiment.
I appreciate all the ideas presented. This forum has saved me a ton of money by informing me or just making me consider things I might have missed! Thanks!