The DL1000 engine was around for several years starting with the the 1997 TL1000, a more powerful version with hotter cams.
As used in the Vee, the engine is just loafing and will pretty much last forever. There are really no unproven technologies at work in the rest of the bike. So no, there aren't any inherent reliability traps in the earlier models.
The only knock against the 02-03 models is the fixed windscreen. I removed mine entirely, but if you feel the need for wind protection your options are far more limited than with later models.
The early model's stator is supposedly a bit less powerful (350 vs. 400 watts is the usual number you see), but there's a strong suspicion that it's also somewhat more reliable, as long as the craptastic Suzuki connectors are replaced or kept free of corrosion. There aren't enough statistics to be sure, of course.
However, the only way to get more power out of the same physical size stator is to use more windings of thinner wire and/or more powerful magnets. Since adding more windings is a lot cheaper than exotic magnets, it follows that the later models DL1000 stators use more windings and may also be somewhat less reliable.
2002 Suzuki DL1000 V-Strom, Dark Metallic Space Blue
1983 Suzuki GS850G, Cosmic Blue
2005 KLR685, Aztec Red - Turd II.2, the ReReTurdening