That's absolutely a defining feature of the ones that do, and it has significant tradeoffs in cost, robustness, battery life & power, etc. Doesn't make it a bad

That's absolutely a defining feature of the ones that do, and it has significant tradeoffs in cost, robustness, battery life & power, etc. Doesn't make it a bad choice necessarily but it's not really like a nice extra. It's something you decide up front that then drastically changes your buying options.