I've used many different versions of both hammocks and tents over the years and they each have their quirks. I generally feel more secure in a tent (as if a bear couldn't get through the fabric if he wanted to

) and they are warmer. I use the tent when my girlfriend comes along as she's not too keen on separate sleeping quarters. lol. Theoretically we could both fit in the hammock but I can't imagine that would be very comfortable.
Hammocks take a little getting used to as they are a clear departure from standard camping procedures. They are colder. Even when it's 50 degrees out you will notice a bit of a chill on your underside. I generally use a 3/4 length thermarest and a space blanket if it gets below 50 degrees at night. Several types of underquilts are available but they aren't cheap. These seem like the way to go but I haven't fit one into the budget yet.
One distinct advantage of hammocks is campsite selection. Most times that I take my tent I spend a good 30 minutes to an hour clearing an area of sticks, pinecones, and rocks before I even start setting my tent up. And even then, the site is rarely level. Not so with the hammock. As long as I have a couple of trees 10-15 feet apart I have a campsite. I hike around in the Sierra Nevadas so this is rarely an issue, provided that I make it back down below 10,000 feet by nightfall.
As far as comfort, the hammock wins hands down. No pressure points. No sore back. I should mention that all of my hammocks are big enough for me to sleep diagonally in, which I feel is key. This allows you to lay flat without your back being bent all night. It does make a huge difference.
Hennessey Hammocks are awesome! They are well designed, they pack up well (get the snakeskins), and their customer service is excellent. That being said, I find myself preferring to use my regular old double-wide Hammock Bliss. This is because, as awesome as my Hennesey is, it makes me feel real claustrophobic and somewhat like a bear burrito. It's irrational I know, but nonetheless, it is worth noting. There's just no quick way out of a Hennessey. They seal up real well to keep the bugs out but that means that it is a 2 minute process to get in and out. With my regular hammock I just swing my legs over either side and I'm out.
As far as storage goes, as long as you use a decent size tarp there's plenty of room to keep your gear out of the weather. I usually just bring an assortment of carabiners and hang everything from my hammock lines. If it's real stormy I put the rain fly on my pack.
Also, if you do go with the hammock use tree savers. No one likes to see scarred up trees.