If this was my first and possibly only trip, I'd want EP for the flexibility and peace of mind it offers. I'd look into the recommendation above on what it would cost for a Premier hotel with free EP for 2 days. In the past that has always come out cheaper than buying the EP separately. Other option is price out EP for one day only and save all the rides with the longest lines for that day and focus on shows, character meets, the parade, gift shops, longer meals, and less popular attractions for the other day.
I've done both trips with and without EP. Sometimes a trip without EP goes great, and with planning, we still see everything with very little waiting. Other times, it is a disaster where we wait over an hour for almost everything and see very little.
I have also noticed recently that Universal is making it very difficult to minimize wait times. It use to be you could arrive early and ride a ton of attractions by 10:00 am. That doesn't seem to work well anymore.
Our last trip we really regretted not having EP. It was supposed to be a slow time, but the wait times were ridiculous, over an hour for so many attractions. I have been during 4th of July before and not seen crowds / waits like the ones I saw this February, so you never know how it will be. I know it was bussier than anticipated, but you could also tell that a lot of the waiting was manufactured by the way Universal was handling things. This last trip really has me contemplating if I want to risk it again without EP. I feel like it use to be very doable with planning, but I'm just not sure that is the case anymore.
If you are ok with 30 to 45+ minute waits for almost everything, than go without EP. Otherwise, I would get it. I would only say skip it if you are someone who is doing a HP only trip. I don't see a reason to pay $$$ for 2 rides, the train, and a kiddy coaster even if you have to wait. There's plenty of time if only there for HP.