Ok I think I found the answer. Unfortunately their site does not have a "Compare" option so I had to open up two different windows to compare.
I highlighted the differences in RED. The differences I see (aside from Flex Pay option and 50% off regular daytime self-parking with Power Pass) are 10% vs 15% discount on theme park tickets purchased at the front gate, as well as additional blockout dates for Seasonal Pass. The Seasonal Pass has blockout dates for all of July for both IOA and USF, blockout dates at USF for "concert dates," and additional dates in April for water park.
SEASONAL PASS:
- 10% off Multi-Day theme park tickets purchased at the front gate (up to six tickets per transaction; not valid on 3-Park Unlimited tickets, Universal Express™ passes or tickets with Universal Express™)
BLOCKOUT DATES:
Universal Studios Florida™
2019
Jan. 1 - 3, 2019
Apr. 12 - 27, 2019
Jul. 1 - 31, 2019
Dec. 21 - 31, 2019
2019 Concert dates*: Feb. 9, 16, 17, 23, Mar. 2, 9, 10, 16, 17, 23, 24, 30, 31
2020
Jan. 1 – 3, 2020
Apr. 3 – 18, 2020
Jul. 1 – 31, 2020
Dec. 19 – 31, 2020
2020 Concert dates*: to be announced
*Seasonal Passholders are blocked out of Universal Studios Florida™ on all concert dates and will only receive access to Universal's Islands of Adventure™. Additional concert dates will be announced at a later date and are subject to change.
Universal's Islands of Adventure™
2019
Jan. 1 - 3, 2019
Apr. 12 - 27, 2019
Jul. 1 - 31, 2019
Dec. 21 - 31, 2019
2020
Jan. 1 – 3, 2020
Apr. 3 – 18, 2020
Jul. 1 – 31, 2020
Universal's Volcano Bay™
2019
Apr. 12 – 27, 2019
Jun. 14 – Aug. 18, 2019
2020
Apr. 3 – 18, 2020
Jun. 12 – Aug. 16, 2020
Please note, Volcano Bay™ blockout dates apply to 3-Park Passes only.
POWER PASS:
- 15% off multi-day theme park admission tickets purchased at the front gate (Up to 6 tickets per transaction per day; not valid on Universal Express™ passes, or tickets with Universal Express™)
BLOCKOUT DATES:
Power Annual Passholders are blocked out on the following dates:
Universal Studios Florida™
2019
Jan. 1 - 3, 2019
Apr. 12 - 27, 2019
Dec. 21 - 31, 2019
2020
Jan. 1 – 3, 2020
Apr. 3 – 18, 2020
Dec. 19 – 31, 2020
Universal's Islands of Adventure™
2019
Jan. 1 - 3, 2019
Apr. 12 - 27, 2019
Dec. 21 - 31, 2019
2020
Jan. 1 – 3, 2020
Apr. 3 – 18, 2020
Dec. 19 – 31, 2020
Universal's Volcano Bay™
2019
Jun. 14 – Aug.18, 2019, before 4 pm.
2020
Jun. 12 – Aug. 16, 2020, before 4 pm.
Please note, Volcano Bay™ blockout dates apply to 3-Park Passes only.