I have some. Not enough ties on long straights, and some fit/QC issues on other pieces. On the positive side, it's readily available at a reasonable price.
If someone wants tubular track and is not in a hurry, I'd suggest looking for it at a meet. Because so many people have switched to other types of track, demand has fallen way off. Great deals can be had on good used tubular track - it's almost impossible for sellers to give it away. And new tubular track is a bargain - vendors who still have it just want to unload it. There's no reason to pay an inflated ebay price, and the cost of shipping track is ridiculous.