Comfort and Hybrid bikes are variations of mountain bikes. Both comfort and hybrid bikes offer a more upright riding position as opposed to a mountain bike which results in a more comfortable ride. Comfort bikes have additional suspension, often on the seat stem, forks, etc which reduces the vibrations to the rider. However, this added suspension adds weight to the bike.
In addition to Trek I would recommend the Giant Sedona DX which sells less than $400 USD. I've been riding one for over two years and it has served me well. I mostly ride dirt trails through wooded areas and I have never had an issue with the Sedona DX.
Find a LBS that will let you test ride their bikes. One LBS doesn't allow people to test ride while another is more than happy to let prospective buyers to test ride their bikes. Can you guess which LBS I do business with?
Good luck in your search.
Best,
Brian