Steve,
I used an Etrex Legend last year too but had a GPS72 mounted on the boom. My glasses / goggles were so fogged up I had a hard time seeing either of them. After the second day, I complained about how I couldn't see the GPS or even past the bow of the boat. David replied "me either"!

I think we'll stay with the 72 on the boom (in a dry bag), maybe the Legend in storage on the boat (it's taken a beating...two RTIs, one Tybee500, one Steeplechase, and tons of tuning / testing data runs on the lakes), and a 201 on my wrist. I'm experimenting this year with different eye wear too.
Chris and I are planning on a run next year too...hope to see you there!