What is there to brag about? Mostly Russians, Indians, Iranians, and Chinese BRAG about their largely unproven STUFF here on PDF.
BASED on
lessons drawn from the Vietnam War, Americans created a NEW GENERATION of combat aircraft (F-14; F-15; F-16; F-18) with both 'super-maneuverability' (powerful engine(s); incredible kinematics) and 'air-superiority' (state-of-the-art avionics; armaments) considerations in mind. Better than anything Soviets could field in the near future. F-15 received the best of both aspects by design in particular.
F-15 have a remarkable combat record in strictly Air-to-Air clashes:
https://migflug.com/jetflights/the-combat-statistics-for-all-the-aircraft-currently-in-use/
F-15
kills include Mig-29, MiG-25, MiG-23, MiG-21, Su-25, Su-22, Su-7, and Mirage F1.
In view of the characteristics of F-15, post-USSR Russia designed Su-27 to achieve parity with F-15 in the 'super-maneuverability' aspect (Americans openly admit as much). However, independent observers cannot PROVE that Su-27 can easily outmaneuver F-15 in low-altitude situations (ONE OF YOUR CLAIMS in this thread). I have posted footage of F-15 variants being capable of excellent maneuvers in low-altitude flight situations and otherwise, in this very thread. Reminder:
https://defence.pk/pdf/threads/su-30-biggest-and-baddest-two-seater-multi-role.651180/#post-12047274
As for which of the two is the superior design? Depends upon what parameters you have in mind. If you look at a jet as a SUM OF ALL ITS PARTS then F-15 is superior by far because Americans have superior grasp of AVIATION-related matters and are able to equip their aircraft with superior avionics and technologies.
F-16 MLU outgunned much hyped Russian-origin Su-30 MKI in strictly Air-to-Air clashes over IOK on 27-02-19, forcing the former to retreat although one was shot down in the exchange. This in itself is sufficient indication that F-15 variants are very likely to outgun Su-27 and other Flankers in strictly Air-to-Air clashes.
Anything else?