They are a fun bike to ride. I actually bet it seems even more so for you guys that also ride bigger, heavier bikes.
My past 3 motorcycles since 1990 have been 600/650 dual sports and, believe it or not, the only other "street" bike I've ever ridden in my life was a 750 Ninja I had to ride home from the impound lot when I was a sergeant in the Army and one of the guys who worked for me got a DWI and was in jail. Other than that, I've never even ridden any other kind of motorcycle even down the street and back to try it out.
I can imagine that after riding something larger and heavier, the KLR really seems light and nimble. Glad to hear you're enjoying the new ride and glad to hear your brother's picking one up. Be sure to post some pics of you guys at the coffee shop with muddy bikes and muddy gear.