Old touring bikes are wonderful bikes and are very capable of taking you wherever you need to go. That said, the newer technology IS better. A lot of the frames are better. When my Miyata 210 was damaged in an accident this summer (tweaked headtube), I ordered a Surly LHT frame and built that up. Well, the Surly is a better touring bike, period. The components have a little bit to do with it, but not much - in the initial build, I used a lot of parts from the old bike. The only downside is that the LHT is a better touring bike
- it doesn't have as much "zip" to it. But that's okay, because the LHT is supposed to be a tourer and my principle commuter, not a speed machine with crit-level handling.
As far as durability goes, I broke the fork on that Miyata and had to replace it not long before I lost the bike for good. I don't know how I did it (I weigh 125 lbs), and I've never heard of this happening to anyone else on a Miyata touring bike, but it did happen. Otherwise, there was never any problem with the bike.