Not sure if I qualify as 'more knowledgeable '... but I have an opinion.
I tried it, and for a rough estimate the tool is brilliant, though for more accurate calculations I would only trust my excel spreadsheet. The thing i did not like was that it does not allow a unit of less than one hour, as if you have induction hob for example, it might be operated for more or less time and the one hour unit is not fine enough (small times with the hob will make massive change).
(My)conclusion : nice tool, not accurate or flexible enough for exact calculations, brilliant for estimates. Ideal for someone without electrical knowledge.
