I have an older GPS (Delorme PN-40) with US maps, and Iíve had it long enough to know how to use it. Only problem is battery life; itíll run 6-8 hours on a set of rechargeable NiMH AAs, which means I need to change them before the end of a 200k. I didn't take a spare set and ran out of battery 10 miles before the end of a 200k last fall, missed a turn in the dark, and added another 20 bonus miles. Not fun. IIRC, the unit I have will go about 10 hours on straight alkalines, which I've been too cheap to use so far.
Iím slow but hoping/working to finish a SR series this year, and perhaps more next year. And REIís anniversary sale is coming up!
Looking at whatís available, it looks like the best choices are either a Garmin Edge (something-or-other) with an accessory pack to recharge the internal battery, or another AA-powered unit like an eTrex or (Random State) 650, which might last 15-20 hours, and carry or buy extra alkaline batteries.
What do you use on rides over 12 hours? How do you deal with battery life? Is it worth the price and effort to learn a new GPS?