We have waited 20 minutes once, an hour the next time. It all just depends on the season, and what day of the week you're arriving. We have found that mid-week airports (and hence DME lines) are the least-crowded. We only waited 5 minutes (and were at the front of the line with only 15 others) last year, and traveled on a Tuesday.
If you're trying to make plans around it - always be extra cautious and plan at least around 2 hours from plane landing to getting to the resort. I usually am very conservative for 3-4 hours after landing before making any ADR's that evening. You never know what could happen to hold you up.