I thought you were running those new "flat proof" Michelins. I know it's a bit off topic, but have you gone away from those, or are they working well for you?
Still running the Tweel's. Put around 2,000hrs on the original set and now have 400hrs on a set of Tweel All Terrains. The originals still had about 1/3 tread left when we switched to the AT's(Tweel's are retreadable, I plan to retread ours when the time comes). Michelin no longer makes the original design Tweel. They now offer the AT and Hard Surface Tweels for SSL's in 12" size as well as a Tweel Turf for zero turn mowers that they signed a deal with John Deere on. The new SSL Tweels do have quite a few improvements over the originals. The spoke shape and layout is different, the "shear band"(piece between spokes and tread) appears larger and the tread pattern is much much nicer. Traction is much better and the ride is smoother than it was with the originals. The original Tweel had a blocky tread pattern that would chatter the machine sometimes.
Still real happy with the Tweel and if somebody has a machine they feel they need solid tires on, I strongly suggest going the Tweel route instead of the solids. The Tweel is expensive, but you have to compare the price to a solid/solidflex tire. Then weigh out the advantages of the smoother ride and better traction. Easier on the machine, easier on your body and less material spilled. They are not the answer to everything, but do have their place in the market. I also wouldn't be worried about Michelin going anywhere. They want this product to succeed, they have dumped a pile of money into it since the 90s and just spent 50 million to build a plant to produce the Tweel. Previously all Tweels were made on prototyping machines and the capacity was maxxed out. If you ever have an issue with one, they are quick to stand behind it. Its a new product, it's expensive and nearly everyone is skeptical of it. They don't want a black eye.
Original Tweel's when new.
Original Tweels after 2k hrs.
New Tweel AT's
Michelin's current Tweel lineup that is on the market. SSL Hard Surface, SSL All Terrain and Turf
The reason I run Bibsteel AT's on the other two machines is due to the fact neither one needs Tweels. For the tasks they do, the Bibsteel's have been working excellent. The steel belting really must help prevent punctures because i've only fixed one puncture in the 3,000+hrs between the two sets of tires (one set is 10" the other is 12"). I will say that while the 12" wear life is continuing to impress me (over 2,000hrs and still decent tread), the 10" did not fare as well. They have around 1,200hrs on them and are about done. I have a set of 12" Bibsteel AT's mounted up on 12" rims ready to go on that machine (226B3). I had the rims leftover from the 262 and the 12" tires were not much extra over the 10" so it was an easy decision to go to the larger tire. The Bibsteel really excels above the Tweel when it comes to ride quality and traction. The Tweels are on a 262D with every creature comfort (air ride cloth, ride control, etc) so the harsher ride is barely noticeable. The Bibsteels are both on older B3 machines that don't offer these features (242B3, 226B3) and thus the nicer ride is very nice and noticeable with the bibsteels. Granted I have never put the Tweels on one of the B3's to compare, just comparing the ride to the factory Titan's. It really feels like you installed an air ride seat once you put the Bibsteels on. Bibsteels are also less than half the money of Tweels with the same wear life, so it really comes down to flat tires. Remember the Bibsteel will resist a lot more punctures than standard Bias SSL tires, but its not invincible as it still has air. Bent rims can be an issue with the Bibsteels, not much more than many other tires, but they still have air in them so its still a potential issue.