It would somewhat depend on which attraction, what time of year, what time of day, and even what day of the week.
I have often used EP (as part of staying onsite), and I would say most of the time my EP waits are less than 20minutes.
I suppose it also depends on what one considers to be 'the ride.' Escape from Gringotts is a little bit like Disney's Rise in that there are very heavily themed pre-shows that might be considered to be part of the attraction. (The only way to bypass the preshows is to do single rider.) I can't say exactly the length of the preshows, but if the ride had no wait at all before the 1st preshow, the Gringotts preshows would still take a solid 10+ minutes.
I also often do re-rides, meaning as soon as I finish, I get right back in line. As with WDW, waits for some rides can fluctuate considerably in just a few minutes. I don't mean just in the early morning, but throughout the day. Many times I've gone on the Mummy with almost zero wait, then get right back in line and the Express Pass wait has changed from under5 min to more like 15 min.
In the last year, I can't say I have noticed a big change in EP wait times, but I'm not ready to draw any conclusions from my anecdotal experince.