I am not really traveller on my DR yet, so far I travel only in Europe - so very much novice, but I got big DR and I ride and maintain it.
I must say that for many many cases when people had dissapointments with Big is down to simply looking after it, it is extremely reliable bike if you know what you doing. If you read stories of travellers it is often amazing how incompetent some bike dealers is when traveller checks in for maintenance or repairs - for example I read that one US dealer was not able to get engine out of frame on Big so filed off some cooling fins
when I saw photo I noticed they tried to do it with carbs and airbox still in frame!
However, I would not recommend DR750. I would recommend DR800, and if possible SR43 (post 1992) and some quite simple mods that transform that bike. Few very serious reasons for dr800 vs. 750.
1. SR43 front forks 43 mm vs. 41 on 750 and slightly beefer swingarm
2. First DR bigs (750) had drum brake at rear.
3. SR43 got 300 mm front disk vs. I think 280 on 750.
4. The most important - DR800 has back torque limiter, e.g. device eliminating biggest problem of DR750 - when stopping engine in case piston has not gone over top point it might go back when stopped, getting engagement with starter gear and heavily banging engaged gears on run back. That causing those engage gears to crush each other gradually leading to total deistruction of starter gear. On DR800 it is resolved by back-torque limitter integrated in intermediate gear and differently made starter gears.
So far My DR800 have 70 000 km on the clock (no, I done only fraction of it as I got it second-hand with 60 k on the clock), was maintained horribly except that good oil and regular filter change was done and had not a single problem in engine apart from regular things - valves adjustment, balancer chain adjustment, decompressor seal replacement. Problems
1. Original exhaust collector box rusted to bits.
2. Some rust on the frame (bike was mostly kept outside),
3. Owner never ever adjusted balancers chain as should be done every 12000km (15 min work), never replaced decompressor shaft seal (15 min work) or head cover sealant (that took couple of hours), ran bike for few years on one of 2 spark plugs and used chains for so long that they ate through chain guide on swingarm AND swingarm (took one evening).
I done some work on it to tune it to my needs, and I can confirm that changing stock exhaust to something like Laser Produro completely transforms it - stock exhaust is whooping 12,5 kg of weight and very restrictive. With cut-out top of airfilter, 132.5 main jets and self-adapted cheap exhaust from eBay it runs sweet and 8 kg lighter.
It does 165 kmph, stock supposed to do 167 but I never really tried above 165. 140 is very comfortable speed.
Speedo is terribly accurate, which I can't explain at all (verified with GPS).
Stock tank is a bit smaller on SR43 - 24 liter, but I cover 400 km to reserve in mixed riding no probs.
Few simple cheap mods can further reduce weight making it overall 20 kg lighter than stock without sacrificing any reliability - this bike really built with too much redundancy.
Bike is unbeleivably comfortable, even 2-up, but coming from sport-ish bikes I am bad judge. Way more conmfortable then DR650 thou, guaranteed.
Suspension suprisingly well mannered on paved roads and bike is very easy to ride.
Front brake caliper sucks big time IMO, but then I am coming from sporty bikes, so I replaced caliper on my DR800 with 4-piston narrow caliper from Gilera Nordwest and made adapter plate myself. Did cost me 15 Euro and brakes really good now.
Crashbars I made from cheap damaged eBay item by changing way they fixed on the bike, same for luggage rack. Bike seem to ignore presence of passenger and 3 panniers set and handles-performs just same as 1-up.
Engine a bit lazy and torque is everywhere, but I've been told that with 36mm Mikuni TMs it amazingly less inert to fast throttle action, so it's down to 2 33 mm stock CV carbs. Economy is better stock.
If you travel far and remote - take spare CDI with you and do some job to lose automatic decompressor. This bike have separate ignition coil and in one event I involuntary tested recommendations I found on Inet about bump-starting it with practicaly dead battery and suprisingly it worked just like on some MX bike.
If you keep oil change schedule and other maintenance schedule this bike will not dissapoint you.
XT660 is great bike too, it's just a bit different class - more like DR650 or KLR kind, DR 800 is more like Africa or Supertenere.
My apologies for long post.