This might be late, I just got a Raleigh Sport bike 2010 for 650 canadian dollars. When i was searching online, shops in USA had them price at $500-$600 mark, and previous models were in the $400-$550 range. My requirements were very similar to yours, it has space for fenders, racks. Summer time it will be used for commuting, it gives a very different and better feel compared to previous hybrids and moutain bikes i used. I also plan on training with this bike so hopefully it will last a few years for me. I don't know about durability, but i like to do my own mechincal work, makes thing last a bit longer than if you didn't do it yourself. My only limiting factor is that i am in no shape to bring out the qualities of this bike, once that happens and i crave for something greater, i'll get another road bike, but for the next 3-6 years i will be happy with this bike.
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under $700 Roadbike, use the search options and the bike names that you want, and see what other people say. As LongIslandTom
MS_AEB:
While I'd much rather go for a bike-shop bike, but if you insist on getting one of the bikes on your list, get the very last one you listed. That one is the only one that will shift gears reasonably smoothly (Tiagra-level components) without sounding like the drivetrain is going to explode.
Better to check out the bike shops (i went to about 12 different ones, finally decided on price, friendliness and helpfulness). Many other people suggest "tiagra-level components" or better, but personally i wouldn't be able to tell the difference. So i got the bottom of the range equipment to see what it feels like. When i do upgrade i know what i am looking for. So far they work very quietly.