Universal handles express lanes different than Disney.
It seems that Disney tries to clear out the express lanes as quickly as possible - even if it means allowing 10 express lane customers to 1 regular customer.
Universal, however, allows the same number of express lane people as non-express lane people on the ride. 10 express lane people get on, and 10 regular customers get on.
So if the express lane is the same length as as the regular line, it will take the same amount of time at Universal. Normally, that's not the case - the regular line is much longer. But if you do find a long express line, it will take much longer to ride than a similar line at Disney.
We went to Universal Dec 19-20 last year, and most rides in express at Universal took us about 15-20 minutes. A few took us more than 45 minutes. The Minions ride took us 80 minutes!!! in express.
Compared to Disney, same time before Christmas, where every
Genie+ we went on was 5-10 minutes in line - save for the Dwarves ride which was about 20 minutes.
I would guess that at low crowd times, express would be immediate at Universal - while in high crowd times with more people using express, the lines would be longer.