I ran 2 1/2" Aerochambers for six years. They were a nice sounding muffler with my various exhaust combinations (1 5/8" shorties, 1 5/8" longtubes, 1 3/4" longtubes).
I switched to 3" Dynomax Ultraflos and a 3" X a month ago. The Ultraflos are a little bassier sounding.