I have both Koogeek Smart Plug and Elgato Eve Energy. While yes, both track energy use, I would recommend Elgato as it meets pretty most of your needs, which you stated:
- record peak draws
- charting
- download data
Koogeek's app offers limited tracking data, just for monthly (all the months for the current year) and daily (only for the last two months). You can't drill deeper than the total daily usage, and as far as I can tell, the app does not offer any way to download the data. Presentation of the data is offered in bar charts and table of numbers. It seems that Koogeek can do better than this, but for some reason they stopped halfway in.
Elgato's app shows the data in hourly or daily granularity in a bar chart form. Actual measurements are accumulated in a 10-minute block. Although the charts can only go back to a certain point (e.g. hourly bars can go back up to three weeks on the "day" tab), all measurements are nicely saved and browsable in a table form. They can also be exported as Excel files to other apps, cloud services, or Macs (AirDrop).
I don't own an iDevices Switch, so I can't make a fair comparison there, but looking at the manufacturer's support page:
https://idevicesinc.com/support/switch/230360568/
Data processed into an "insight report" form seem to be the app's strong point. However, it's not clear if the actual underlying data can be browsed as easily and a quick internet search was inconclusive.
Lots of smart outlets/plugs claim to "track energy use", but I have yet to see it done as comprehensively as Elgato Eve.