My opinion on them is: Don't use them. Think about it this way: The lower the ABV of a beer, the more you can enjoy before getting trashed. It's wonderful to be able to enjoy British Milds or Ordinary Bitters pretty much all day long without ruining your liver, getting a nasty headache, and wake up to stange people in the morning that may or may not be diseased, unattractive or of the same sex as you are.
The standard ABV in most beer styles is optimized for the flavor characteristics that makes each style great. Pushing it beyond the limits, especially with sugars, rarely yields a superior result.
If you just want to get wasted, drink spirits instead.