I have an alternate theory on the paddle length: the distance of your arms. I'm 6', but have monkey arms. By height, I should be rocking a 197 or larger, but that feels impossibly long. My 194 feels long when in use, and I like the feeling of the 191. If I'm in the playboat, I'll go down to one of my 188s.
BTW - it is also a commentary on the addictiveness of kayaking that I own four paddles and four boats, only half of which get used.
Nurr - When you are trimming out that boat, pay a lot of attention to the hip and knee areas. These are your primary control points. Use the footblocks to set the tension, and the backband to finetune it. You should be comfortable for about 30 minutes at a stretch. If your feet are going numb, check the hip pad. It is likely to be pinching on the hip, so slide it backwards in the boat a bit before reducing its size.