I'm looking for a breakdown paddle and am curious what others think of the few on the market.

Look at Lendal's Emergency Paddle. They bumped up there prices this year to $210, but you can still find them at the old price of $175. They are 197-210 cm, have a fiberglass shaft, and plastic reinforced plastic blades. They are half a pound heavier than the Werner break down, but are easily equal in quality.

I had an Auqabound breakdown and broke it paddling normally. They are cheap, but will work adequitly as an emergency paddle. Nothing more though and treat it gently...

It does no good when you need a breakdown to have one that breaks.  I've seen this with Aquabound, and frankly, they make a substandard product in every way, but you do get what you pay for.  What price can you put on safety?  Would you buy the cheap PFD; the cheap throw bag?

Yeah get the werner, would be my advice. For me personally if I break a paddle, usually It'll be in some harsh environment, where the performance and sturdiness of any paddle matter. I wouldn't go so far as to say you can't put a price on that, but it's certainly worth an extra hundered or two if it'll get you the rest of the way through the trip without greatly sacrificing performance, and the comfort of hitting your lines in a reliable manner because your breakdown is a real paddle, instead of some spongey piece od plastic. But 4pc is the way to go for sure, then store it sealed & dry to keep sand and feign matter from getting on it. 2pc units don't often fit in the back of my boat.

If your still using the Rio, I sent mine back to werner and they replaced the blades.

Yup. For me personally, I'm likely to lose or break mine in class V water. I'd want comparable performance to remain comfortable after such an incident, because if said incident is bad enough to break or lose a paddle, it might be enough ro rattle my confidence and spook me. Having a decent paddle to use afterward would at least minimize any potential head games that might bounce around in my brain.

And, if my limits were in class IV water, I'd likely feel the same way. I am who I am and my temperment is what it is. I'd forget all about weather I saved an extra hundered bucks or not. It would be all about getting through the run and having an enjoyable day.

On class three,  fluke things can happen. But if you're breaking paddles on class III water you need to take a hard look at your technique, and go back to the fundementals. If you lose paddles on class III, you need to look at who you are paddling with. Competant class III paddlers should be able to chase down a paddle in class III water. Still, fluke things happen, and black carbon fiber werners are hard to see. (My only complaint about them )

Werner 4pc!

Hand paddles are always an option. Light, compact, they don't break and easy to store in your kayak.

Is it practical for you guys to use a 2-piece paddle as a spare? (I'm an IKer, so I have the room for one.) I use 2-piece Werner paddles as my main paddles, and they work great, so if you can stow it, that would seem to be a good deal.

I've had the same experience with plastic-bladed paddles breaking. Also, keep in mind that a 4-piece paddle takes some work to put together. A few years ago, I was in a situation where I dropped a paddle while going into a rapid, and I needed to get my spare put together so I could get to it. I ended up dropping one of the shaft pieces in the water and couldn't see it. I had to canoe paddle and I never did find the shaft. I really should get reflective tape for those black paddle shafts...