No surprise about sluggish performance .. though I don't think it has anything to do with the supposedly lacking hardware, as they claim.

Something far more worrying, though:

"A 30-minute charge will give roughly just over 10%".

That's absolutely awful. Basic hardware platform may be standard in these Intel tablets, but going with a small, cheap OEM can result in other impacts on performance. Can't imagine any of the bigger brands performing that woefully on the charging front in this day and age. Some smartphones with 4000mah batteries fully charge in ~60-70 minutes these days. 4400mah 30 minutes for 10% is beyond bad.