2 cents coming in...

There really are no 'shortcomings' with the LEVEL 2 CB500X when it comes to the kind of 'off-road' riding you'd be attempting on a travel bike loaded with luggage - it will eat up everything you're going to be prepared to ride on an overland trip.

Equally, the DR650 is a great dual-sport bike that can also rack up serious mileages on RTW style overland trips - loads of aftermarket support, cheap (especially secondhand) - although you'll have to do quite a number of modification$ to a stock one to get it anywhere near approaching the on-road comfort and high-mile-munching ability of the CB, and it will still never be an EFi twin.

However, if you're also going to ride it unladen, just for fun, then the lighter weight of the DR is going to potentially give you a little extra margin for mistakes off-road, but don't discount the excellent and engine and transmission on the Honda - it makes it very easy and forgiving to ride off-road too.

Both bikes have been around the world, the length of the Americas and Africa too... If I was embarking on a long-distance trip, I would the CB every time. If I wanted to play around off-road and trail-ride at weekends, it would also be the CB - but the DR is great for that too ;o)

As others have suggested - it's probably best to get a ride on both if you can, see how they fit you, and tot-up just how much you'd need to spend on either to get them to the specification you desire for your planned trip... don't forget you can pick up used CB500Xs for around $3000 these days too now (the first ones came out in 2013).

Ultimately I consider that either will serve you well.

Jx