You need to focus more on the size and installation of your air conditioner, rather then a high end air conditioner. Since the big factor is the installation, if it is not installed appropriately, you will face more problems later on.
One great reason to have a correctly sized ac system is humidity control. When it operates, the evaporator coil temperature is below the dew point temperature Go to their site . The result of this is that the moisture condensing on the evaporator lowers the moisture in the air. This would mean a reduction in the humidity. This process cannot happen with a large ac unit, as the run cycles on them are too short for this to take place. So keep that in mind when youre going shopping around.
Also, maintaining and fixing an over sized ac unit can cost you much more. The compressor for example, gradually, will wear out and you will have to get it replaced. If your ac unit switches on and off for 4 or 5 times in an hour, instead of the regular 2 or 3, it will wear out your compressor. There are numerous other factors to keep an eye out for when shopping around for an air conditioning unit, so be sure to do some research and not hesitate to ask questions.
Now, at least you understand its not all in the name. Make sure to pay the additional money and get the air conditioning unit installed appropriately, because that is the main thing. Sure, there are other factors, but, not everybody has the budget for the air conditioner with better attributes. So getting it installed appropriately will save you quite a bit of money down the road.