The disk brake idea is a no brainer ... the air ride pin box works good for us as well. Slipper springs ... the jury is out for me as far as an RV application. I have slipper springs on my boat trailer and both our 32' and 40' gooseneck farm trailers. Be aware that they can be noisy traveling down the road and the ride judging from the rear view mirror isn't a very smooth one. But hey, our John Deere's and implements that fit aboard the trailers don't seem to care.
Slipper springs are designed to carry heavier weights better so I've been told.
Remember this about forums and postings. You mostly hear from people with issues and not with smooth sailing experiences. So you do read about a dozen spring related failures ... I agree it is concerning to those to whom it has happened, but what about the other 1200 people that have had no issue with their suspensions that remain silent about their experiences?
Also remember reviews on products in magazines have an underlying agenda to present a product in its very best possible light generally. Actual mileage may vary after installation and usage.
It makes one wonder why slipper springs aren't even an option on most RV's at least that I'm aware of??? Is there an application reason .. or just the canned offering of the frame manufacturers?