I've never heard of the long chain spewing mud thing! Ha! That's a new one!
Bents as a rule may not climb as well as uprights partly because they tend to be heavier and also because you can't stand on the pedals. But you compensate by gearing down and spinning. I tell new bent riders that on hills drive it like you would an underpowered car. Gear down and keep the rpm's up!
My new bent, a Rans V3ti is very light, almost as light as my wife's carbon fiber upright, and while she used to pass me on hills (I'd pass her on straightaways and donwhills) I can now keep up to her and sometimes pass her because of the light weight and custom gearing on it. And she runs marathons and does cycling classes all the time which tells you a bit of her "engine" on that lightweight bike!
I first bought a bent because of severe back problems and now, even if I could get a brand new back, I wouldn't go to an upright, except for mountian biking. Bents are too comfortable, not only for your back and neck and hands and...........etc. No comparison at all.
I used a LWB bent with a rather upright seat for my back problems and it worked really well, maybe even better than a more reclined position. But everybody is different and its great to try different styles.
For a variety of silly and invalid reasons (except maybe jealosy) upright bikers tend to look down on bents, although as more are trying them, this is gradually changing. The racer groups are the worst for this. So you will hear a lot of nonsense about bents, 90+% of which is not true. Bents aren't much for off road mountain bikes though.
But a bent for your back? I wish I had discoverd bents years ago. If I had, I truly think I would NOT have had anywhere near the back problems that I ended up with. I sometimes partly joke that if I were in change of pre approval for an HMO or medical insurance plan that I would insist on 3 to 6 months use of a LWB recumbent before any surgery be performed!