I was just at Stella going to the legacy parks, so the opposite. Going between the two parts of Uni's property takes a bit of time.
You are well versed in how long it takes to get around WDW. Getting around IoA/US/HRH/RP/Porto/CB/Aventura/SF/Citywalk is all pretty quick and easy. Getting between the Epic are and the legacy area of Universal takes is very doable, but it takes a little time. It would depend how you factor that into your personal planning, and the park hours.
My Epic experience was coming from Helios in summer, so it made sense to arrive for rope drop. We were about 5 people from front of the line for Mario Kart with Stardust was down most of the day. It was summer, so storms rolled in both days. Taking an afternoon break was somewhat essential, because much of the park closes during storms, and we had the convenience of staying at Helios.
My visit was also before the new ticket policy; I'm sure more people are park hopping now. There is probably a PM change in crowds while the weather is cold. I could also see people flocking towards Epic in the evening on a nice night. We saw people taking advantage of Early Entry in IoA then leaving for Epic.
Generally, I would say the weather is an important factor for days in Epic. Much of the park is outdoors, and much of the park (like AK) stops running during a thunderstorm. As with WDW, you can sometimes use that to your benefit.
My other big tip is to take time to appreciate theming. Universal did a great job with little details all over the park. It is easy to get caught up in rushing from ride to ride to minimize waits, but the park has many high quality, non-ride details. Personally, I'd want my first Epic day to be as full as possible so I have time to explore the non-ride parts of the park. Dark Universe has superb landscaping. The H Potter land also has many small details that are fun to explore, like all the new wand spells.