I looked for ages for a modular. I tried Shoei, Shark, Nolan, HJC, Vega etc. etc.. They all fit differrently, even different models within a brand. I tried the Nolan 103, trilogy and hated them, Didn't fit at all. The N90 fit excellently and is very comfortable. I purchased it and am very pleased. I always wore Shoei beforre that and wanted the Multitec but the chin bar was to close to face to make a microphone comfortable so think about if you are going to use a communications system as well.
Like they all said, try them on for more than 15 minutes and choose the one that fits best for you and has enough chinbar mouth room if you are putting in a communications system. Also, although I use Edsets and love them , I'v also used J&M. If you want J&M, make sure the top of the line speakers will fit in that particular helmet. They will not fit in all helmets and the lessor speakers aren't very good. Just my two cents.
2007 Silver GL1800
2004 Red Honda Reflex (Wife's)
IBA # 33890