Joey Hannes wrote an answer about Five Ten Anasazi VCS Climbing Shoe - 2012 Model on March 27, 2009
Probably. Since they are comparable models within the same brand I'm sure the sizing is pretty close. If the 8.5 were too tight then yea definitely go up. Although finding a local vendor that has them would be good so you can actually try them on. Anasazis are found almost everywhere. Try them out in person if you can then come back online and get a better deal!