Think I have the final lineup for the shoot out now: M100, Philips Fidelio L1, Sennheiser Momentum, Skullcandy Aviator.
All are reported to have good bass with extension and impact but also controlled. Other desirable qualities for me, smooth but detailed mids and highs. In line remote is a must (which is a bit of a mark down for the M100 as the 3 button is extra). Must be easily drivable from iPhone 4s and iPad without amplification. Not too big but comfy and ideally good looking.
Just waiting for the M100 to be released over here and battle can commence. Any thoughts most welcome.
I have heard, owned or own all except the L1. While the Aviator is a very good sounding headphone, I don't consider it a basshead can and consider them fairly neutral. On bass alone, I would take the M-100 over Momentum as M-100 bass is much tighter, deeper, punchier and less intrusive in the mids. As an added bonus, I prefer M-100 throughout the range. I have heard the L1 is warmer/darker than the others.