I fly with the Clarity Aloft Classic, which looks very similar to the Halo. The big appeal to me with in-ear headsets was that I can wear them for 5 hours without getting a headache. I've tried a few different DC's and a pair of A20's. All of them gave me a headache within a few hours, possibly because of interference with my glasses.
Another reason I ended of with the in-ear headsets was that I was lucky enough to be learning to fly in San Diego at the time, and Marv Golden Pilot Supplies let me borrow one for a day to go try it out in the air. If you have a pilot supply shop nearby, ask them if you can do a demo.