We were Disney fans our whole lives, going every chance we had. I think I've been to Disney parks twenty times + on both coasts. We just went to Universal for the first time in January. Having stayed onsite at both places, we are now die-hard Universal fans. There are many reasons for this.
1. Quality requires funding. Universal and Islands of Adventure were pristine. The parks were clean, the rides were all working, and everything was running on schedule. The environment they created implemented so much detail in so many disciplines - art, mechanics, construction, design, electronics, etc. It was on a level equal with what we were used to seeing at Disney. In some places, better. It was delightful and showed a lot of conscientious work being done behind the scenes. They know where it's smart to spend their money. Someone at Disney decided to drastically cut costs and still raise prices. On our last trip, the monorail wasn't working for several days, there were burnt out lights in MK that were never replaced the whole time we were at the parks, rides were breaking down and no one was running down the line to tell you how long the extra wait would be (the way they used to), etc. And there was trash all over the place. They didn't realize that cutting back on things like maintainance, quality of merchandise, number of trained employees, etc., makes the Disney experience much less magical than it used to be.
2. The resort hotels are better. At Universal, we stayed at the Hard Rock Hotel. We stayed in a kid's suite, which was actually four rooms (2 bedrm 2 bath) and a big entryway with a big closet and fridge. The suite was huge compared to every Disney room we'd been to, and cost less than our tiny rooms at the Polynesian and the Grand Floridian. We stayed at all of them in the off season, so the price difference was an accurate comparison.
3. The staff at Universal was happier and better trained. The hotel staff at HRH anticipated our needs, answered all of our questions, acted with courtesy, and were happy to be there. The park employees showed the same friendliness and knowledge of their jobs. On our last visit to WDW, they had a dozen people standing at the concierge desk who all kept running to one older man peppering him with questions about the computer program, benefits, reservations, etc. When we had a few problems with the vouchers and tickets that came with our package, no one even attempted to solve the problems. Their immediate answer was, "There's nothing I can do about that." No one had the authority, or even the desire, to solve any problems of any kind. The staff was walking around talking about how much they hated the management IN FRONT OF THE GUESTS. If the employees are so unhappy that they think it's okay to talk like that in front of guests, you know they've got some real problems.
3. Resort perks. Our reservation at the Hard Rock Hotel included park passes, and some really significant perks for staying onsite. The Front of the Line perk for the rides and priority seating at restaurants just for showing your room key are fantastic! You also get discounts and better seating for shows at City Walk, discounts on merchandise, and they add special promos that change every season. Our promo was free kid's meals at the hotel restaurants. They really spoil you for staying onsite, and it makes it a wonderful, easy experience worth repeating.
4. Simple is better. Using our benefits while we stayed at the HRH was so easy! It was all included on the room key. Everything was well organized and explained in our welcome packet, the employees knew the packet and benefits very well, and we had very little extra thinking to do. That really matters when you're in an unfamiliar place with a seven-year-old and a two-year-old. Our last Disney vacation package was a nightmare. We had to organize a huge pile of vouchers they sent in the mail a week or two before the trip, and then try to keep track of them and carry the right ones to the right places. It was really impossible to get what you had paid for, and there was no way to replace a lost voucher or ticket to a show.
In summary, Universal was better operated, better organized, better maintained, had MUCH better perks, and was really a better deal. More magic and happier people. That's what made the biggest difference to us. Oh, and the great roller coasters....