... I was also leaning to an SWB because I figured it would be more stable on steep climbs, but I'll try out both. Thanks again for your help.
The last time I bought a bike that was going to be used for touring ('07 Rans V-Rex), I tried a number of other bikes. My litmus test was, would it each machine handle well towing a loaded BOB trailer? One LWB that I tried was fine going uphill at low speed, without the trailer. With the trailer, it was almost uncontrollable. So if you are considering a trailer, also test ride with a loaded one.
p.s. We don't use the BOB in hilly areas, only where it's relatively flat. Actually I've been sold on underseat racks. Handling is unaffected, it's a really slick solution. Combine that with taking as little gear as possible, and you have a winner.