WaveCut Audio Editor is an enhanced version of the free audio editor for Windows from the guys over at Abyss Media. With greater speed and multi-window interface, it remains nearly the same; compact and easy to use.
Most basic operations performs instantly without causing any delay. The developers collected suggestions from their users for a long time and have made hundreds of improvements in all aspects of audio editing in the app.
WaveCut Audio Editor is easy to use with an uncluttered interface (for a free program that is). The app can perform most operations with relatively no delay. The audio format support is very good with most popular formats covered.