The new model may very well be lighter and have nicer components - its been 10 years since you bought the old one , so no I don't think its crazy to think about getting the same bike over again -one thing though, the diameter of your tires shouldn't make much difference in regards to cracks/potholes etc.... 650's may not have as great a selection of widths as 700's but the issue is more one of having wider tires, not bigger wheels.