Last time I went, Universal Express was really just not working well. I had an annual pass, and the booths were down quite a bit. Also, when they were up, as someone pointed out, the rides were often walk-ons.
I DO think, though, that Universal's front-of-the-line access for resort guests is very successful. I spoke to several groups staying at Universal that spoke very highly of the perk. If I were to guess, I would say Universal Express goes away somewhat soon (since the payment option has not worked well for anyone really - namely Six Flags who has done it for a few years now), and the front-of-the-line will stay put.
I also think that Disney has, for some reason, cornered the market on this. I understand the gripes people have about Fast Pass, and it does make lines longer to some extent. However, I think it psychologically makes the wait shorter. I always feel like I get a great deal with those pieces of paper. So, even if I am physically waiting more throughout the day, it feels like I am not. And that is just as important IMHO.