One thing I know about Hobie is they have the best continuing improvement program on their products that I have ever seen. I also know they monitor these forums and pay attention to details very well. I've been using the mirage drives since 2007 and have never had a serious failure with any of my dozen or so mirage units I have owned. I'm a pretty heavy user and typically pedal my TI at least 15 miles per week all year round (it's my exercise program), some weeks like when we are down at our key west house, I'll go out every day if I can when there.
Just in my experience pretty much every suggestion I have made regarding product improvements or potential problems have mysteriously appeared on their new products or are corrected usually within a year or so from when I posted them. I assume it takes Hobie about that long to re-design, fully test, then re-tool for production. Often times this requires new molds and tooling which are typically extremely expensive (I'm in that business). I have a sneaking suspicion that this mirage shaft problem will just quietly go away as Hobie works out the details with their suppliers, all behind the scenes and transparent to the rest of us.
Tom has a good point, and he has mentioned this before, that we mostly only read about the problems that people have, and very seldom about successes. I follow this forum and only recall reading about mirage shaft failures being reported, as maybe 10 that I have read about since 2007. I'm sure there have been more, and since everything Hobie is covered by their wonderful warranty program, chances are every one of those bad shafts were replaced promptly, and the customers are now very happy. Hobie is a major manufacturer of kayaks worldwide and I wouldn't be suprised if they are selling well over 100,000 mirage drives per year, that times 7 years is almost 3/4 of a million units out there with 10 failures (that we know about) since 2007. Any company prays for a failure rate that low, even with that I can pretty much guarantee we will see the shaft breaking problem going away quietly very quickly as Hobie hones their manufacturing process to cover that .0001 percent of users with fishermans feet ( Hobie calls it fishermans feet because when reeling in their fish they often brace their feet on the pedals with the pedals in the center (I have caught myself doing that) this puts excess stress on the mirage drive shafts, thus their term fishermans feet).
When out we all have to be prepared for failure, and have backups for everything including the mirage drive (ie.. paddle on board always).
Just 3 days ago I had a catastrophic failure while out at sea 10 miles from launch. I ran into a 300 ft wad of heavy test fishing line (that green really strong stuff) floating out in the gulf. I was flying along minding my own business when all of a sudden the line got caught up in all the parts of my boat, then started winding onto the propeller on my motor, the line was all over the boat and as it pulled tighter (winding up on the motor it tore one of my hydrofoils off, bent the fin shaft on my mirage drive, broke the rudder pin, and tore the propeller completely off the boat (wrecking the lower unit, and losing the prop). It took me over an hour to untangle and cut the line from everything, straighten the mirage drive shaft, replace the rudder pin, remove my foils, then sail and pedal the old fashion way the ten miles back from the open ocean in almost no wind (maybe 4-5 mph winds at best). So it's important to have backups of everything ( I always carry an extra mirage drive, and paddles) because you never know what's going to happen out there. My planned under an hour trip turned into a 6-7 hour painful and expensive ordeal, but hey I still had fun out there. I'll be out of commission for about 2-3 weeks as I repair everything though. I keep a spare prop on board (more redundancy) but the lower unit was damaged so I couldn't run the engine.
One of the rear foils was destroyed, now I have to make a new one, plus wait 2 weeks to get the motor repaired.