For those that do try and hammock, many will find they sleep far better than in a tent (or even their own bed!). My wife and I both have been using hammocks for the past 10 years or so. We started with Hennessy and upgraded to Warbonnet Blackbirds and now have slimmed down to the ENO Sub7 (hers) and a Dutchware Gear Halfwit (for me). We still use our Blackbirds for really buggy locations and our primary "winter" hammocks when paired with under-quilts.
Once you get passed the learning curve of properly setting up your hammock, you'll find you can size up the best location and have your hammock positions and setup extremely quickly. I've upgrade to a cuben-fiber rain fly which I love (but it too sounds like a tin roof in a heavy rain
). The rain fly is equally as important as the hammock and the beauty is they can be put up first and taken down last, keeping your entire camp area dry. For hot, humid weather, several allow you (canary cut) to set up an awning with trekking poles which allow excellent air flow. For colder, winter camping, you can get flies with "doors" to seal up just like a tall tent.
I've never had a whoopee sling failure, but I did try the very light Kevlar tree straps which I will no longer trust. I had one get a slight puncture/tear and it compromised the entire strap resulting in an embarrassing failure of sitting in the hammock and ending up on the ground
. For our "repair kits", I carry an extra whoopee sling and my wife carries an extra webbing tree strap. I've actually traded one pair of whoopee slings to the ENO Helios set which are a pretty decent design.
I've found my backside gets cooler these days, so if the low temps are below about 55 degrees, I'll pack my JRB under-quilt. It's a one-pound weight addition, but makes a significant distance in comfort in cooler temps.
The comfort of a hammock is more than just for sleeping. After a long day of backpacking for 15 miles or so, it's nice to just set up the hammock and relax with your feet elevated. You can also (with most designs) just use the hammock as a chair to either lounge or even cook from. If it's raining, once I get my fly and hammock up, I can store all my dry gear in the hammock until I'm done making some dry storage areas on the ground...I find I can stay far drier backpacking in wet weather conditions with a hammock than with a tent.
The other nice feature of hammocks designed like the Blackbird, is that they can still be used on the ground. I've used my trekking poles to just erect my fly and keep the corners of the hammock taut. The hammock body rests on the ground (preferably on top of a ground cover) and acts just like a bivy bag setup not requiring any supporting structures other than my tracking poles which just maintain a bivy shape (they don't support any weight).
Glad to see you "convert" your friend and I hope this helps him get into the outdoors more often. Good choice on the hammock as well!
ROCK6