If feasible, then I'd advise not trying to get a do it all bike, get something for the commute only. If you get hooked you're going to want something fancy for weekends anyway. Looking at a commuter I'd consider, guards, rack(if you need to transport laptop etc) and lights. I also went a step further and had a hub geared wheel built, 9 speed, in the interest of low maintenance. My commute's a 40 mile round trip and I will rarely use more than 3 of my 9 gears, sometimes only 1. Though I suspect that, come Winter, I may be glad of the extra gearing. Next Winter I may consider going with a dyno hub front wheel.
Comfort is important for me as well, my steel frame bike is definitely a softer ride than the alu/carbon mix I used before, especially when weighted down. Tyre size makes a difference, I use 35mm M+ tyres, chosen for puncture protection. Though they have done 'what it says on the tin' they are very heavy and don't roll brialliantly. I'm looking at a new commute tyre, don't know what yet, but still considering a wider model.
If you get a bike that's great for the commute it probably won't be so great weekends and vice versa.