This has all been really helpful. I think I am going to try a few more runs on my friend's 67" and see how feels. If it seems too big, I will see if I can get on a 65" or a 66" Vapor (or any other 66"s anyone can recommend!) Truly appreciate all the feedback!
He had a 67. Nice ski. Way different feel obviously from the Siege, but there is a lot more than just the length affecting it. I might check out a 66" Vapor, too.
My weight is pretty consistent. I'm 58 years old and have gradually increased my skiing speed over the years. Generally, I'm on open water, but occasionally ski the course.