You know, a lot of it has to do with boot size too... I mean, if you rock size 14 feet and need a boot sole length of like 360, the din goes up.. like, waaay up..
I have a 305 sole length, rossi axium 140's, weigh 145-150, and I am 6 feet tall...
Therefore, I have a 6.5 din setting, and thats what the ROSSIGNOL BINDING ISC CHART SAYS IT SHOULD BE.
I am a Vermont Ski Assiciation trained Ski and Snowboard technician... I work at a ski shop and reset bindings every day I work.
All I can say is, if you set your din higher, you should definitely check with the local ski shop guys first (assuming they know what the fuck they are doing) about it, so you dont rip out an ACL or something...