Comfort bikes are a variety of hybrid with reduced emphasis on performance and with a more upright seating position, The tend to be designed for less strenuous riding and may be heavier. Another variety is the straight-bar road bike like the Specialized Sirrius which is aimed for high performance with thinner tires. Avoid front suspension because unless you will ride rocky terrain. You can obtain the comfort you desire through tire selection, without the weight of the sprung forks. Tire width is cheap to change after you get your bike. Look for more advice on the commuter forum. Good luck.