I used a set of Dunlop 603 on my 640 on a trip last year.
I only put them on because I had them sitting around and I needed to ride 2500 or so Klms of tar and I thought I would burn through them before fitting some better rubber.
I ended up leaving the rear on for the the whole week I was riding around Tasmania, had a brand new Michillin T63 that I was carrying on the back but was happy enough with the 603 that I didn't bother to change it until the return leg.
Front was used for the whole trip.
Next set of tyres I get for my LC4 that I will be using for a work hack will be either 603s or 605s.