Question about dual purpose bikes (Honda XL650...etc)

Hi all:

I am considering buying a dual purpose bike, basically one of the street
legal enduro bikes. I think Honda's latest is the XR650L.

I do mostly highway riding, but I would like to do a bit of off-road/trail
riding. No real extreme offroading, just have the option of going off-road
exploring now and then. I was wondering:

1. How good or reliable or durable these things are for any sort of
long-range highway riding.

2. They are one-cylinder, right? Do they have decent power?

3. Are there comparable bikes? I wouldn't mind being able to carry some
gear along.

Any advice would be appreciated, thanks,
Garry,
Calgary.