WHAT??? A 5-digit counter has lees chance for errors?
When measuring a marathon course, my click-count is about 471,960. That means that if I start at zero, my counter rolls-over 4 times. If my counter was above 72,000, then I would have the hundred-thousand digit with 5 different values.
When entering your target counts prior to the ride, having that 6th digit makes the math easier, whether using a spreadsheet to do the math, reducing the chance for human error, or using a calculator to determine the values.
After the ride, when verifying the second set of counts, having the 6th digit makes it simpler for both a humand using a calculator, and also for a spreadsheet. If one argues that "you assign the 6th digit" when doing calculations, that is increasing the error risk, not reducing it.
I suppose if one is only measuring 5k courses, and doesn't begin measuring when clicks on the counter are over 50,000 at the start, a 5-digit counter has no disadvantage. But, how often is that the scenario?
I advocate 6-digit. I will order 6-digits. The less room for error, the better, in my book. There are enough distractions when measuring.