I have heard that LRs tend to eventually have suspension problems. Specifically on the LR3, is this typically a matter of the compressor? Or is it the bags/bladders themselves that leak?

We had a Mercedes GL once (big mistake), and we were replacing both of these components routinely. The compressor burned up once, and then over the course of a year, every bag on every wheel eventually leaked and we replaced every bag at different times. We knew it was time to sell the car when only 6 months later we started that process all over again.

 

Short of getting a dud or cheaping out on a Chinese eBay part replacing the bags or compressor are a one time thing.

And if you're still not sure about it, there is a coil over replacement kit for a grand and you'll be clear of air ride worries

 

Its a pretty reliable system. And as advanced as it is, its still pretty simple to repair. The absorber inside the strut will typically wear out before the bags do. I know in one thread people have been reporting over 150k miles on factory struts with no issue. The compressor I would personally "rate" at 100k miles before a rebuild is needed. A rebuild would include new desiccant material in the dryer. If that material is let to degrade, it breaks down into a fine material that can contaminate the system - this causes the second vulnerable parts to fail, the valve blocks. But if a compressor is serviced before it becomes a problem, I could see them lasting a long time. Rebuilding is not terribly hard, there are even some kits that have most of the parts. And the valve blocks, again easily rebuildable with new ones costing around $200. There are two valve blocks and one proportioning block. A $30 kit can rebuild all three.

With all that said, anything can happen. A bag can leak at any time. A compressor can fail without warning. But I dont recall anyone on the forums having the "routine" issues like you had on the Geländewagen.