Big ups to PNW! I've been on my Rainer post for 3 years, and it has been fantastically reliable. Of the few times when it has become saggy, or failed to return to full height, all it has required is pumping back up to pressure. Well worth noting that by the time the post was getting to this point, it was nearly 100 psi lower than recommended, yet still managing to operate. Based on my experience, I'd say they have good reason to be confident in offering a lifetime warranty on their products.
The Loam Lever is also far & away the most pleasant feeling dropper lever I've ever put a thumb on. The "yoga mat" thumb pad is much more enjoyable to the touch (even with gloves on) v. the various machined patterns on other dropper levers.