I am thinking about the FX range.

I am looking to replace an old Trek 800 mountain bike as a commuter. I ride 15 miles round trip. I am looking for something that is more efficient to ride. I have a Trek 2.1 in the stable that is a great road bike for me. So, the new commuter is in a delicate position.

It needs to be fun and easy to ride. I am looking to reduce my commuting effort.

However, it will be a commuter. I will be tossing fenders and a rack on it.

It also doesn't need to be top of the line. I have the Trek 2.1 that is more than enough road bike.

Therefore, I am thinking about the Trek 7.0 - 7.2. However, I can't find a good list of the differences. Is the 7.2 the sweet spot in the range? It sounds like it has metal pedals (which may be junk anyways?) and puncture resistance wheels (that could be worth ~$80).

Model recommendations?