The performance was what I expected for 5v, but 5v is 5v, and there are plenty of alternatives that will run at 5v. Your Darwin being one of many.
If a person wants to find out what 5v vaping is like, my advice is to get a little $40 box mod from MadVapes and a box of 3ohm Boge cartos, and see if they even like it before they invest a whole bunch of money.
My personal description of 5v vaping is that it's like drinking strait shots when you are use to drinking mixed drinks. I think most new users will want to turn it down to 4.5-4.7v or so