I got the GMAX GM11D. Granted, I'm still a newbie, and I have no seat time with other helmets, but guys here is my 2 cents. I bought my TW recently and borrowed a buddy's extra open face to get in the saddle with. Since then, I have been trying to find myself a good helmet. I thought I was going to get a AFX FX-39. In fact I did, two of them. I really wanted that helmet because I thought it looked cool, it was affordable, it got great reviews, and it seemed to be the "hot" choice. I feel that both the AFX or GMAX are good choices.
I chose the GMAX for these main reasons: 1) I am a glasses wearer, and my riding glasses particularly have thick frame arms. The GMAX allows me to slip them right on and they fit comfortably, while AFX had a slightly higher area in the cheekpads that made my glasses tilt downward, as well as pressing them hard into my head. 2) The visor on the GMAX goes up completely out of your field of vision, while most of these dual sport style helmets have a clearance problem with the peak forcing the visor to be down slightly in it's raised position. 3) Fit. While I got two FX-39s and multiple cheekpads to try to get it to fit "right" I just couldn't find a sweet spot and sent it all back. The GMAX didn't fit perfectly mind you, but close, and without dinking with cheekpads, etc. 4) The FX-39 has a ratcheting clasp on the chin strap, while the GMAX has the traditional double d-rings. Also, I felt like the chinstrap on the AFX was farther back trying to choke me. Your mileage may vary.
After a little seat time, I like it. I've mostly ridden with the visor up, but it is nice to have when you want it. I got mine from Amazon for $103. Thanks!