Done 3500ks on my DR650 and recently modified the airbox with nice improvement in breathing. In fact it made a big difference.
My other bike is a Triumph Thunderbird with 35000kms, only mod is Staintune pipes.
T'bird isn't the fastest bike on the road but it ain't a slug either. The DR can keep up with it everywhere except off the line.
I'm really surprised at how easy the DR accelerates and performs generally.
Australian bikes are fitted with 16t/41t sprockets, which really allow for quite comfortable highway cruising.
For $aud7500 all up, I reckon they are a bargain.