I got a LÜM-TEC with tungsten carbide case. While I like it initially, I was soon turnoff by the crown. It's too big, so it rub against my skin, and got itself loose. Water got inside the case. I sent it to LÜM-TEC and got it cleaned and oiled, but they did nothing to the crown. I got loose crown and water again.
I got a friend with same size LÜM-TEC stainless steel case, and he got the same problem. He send it to a jeweler, and it had been fixed.
One other thing wrong with my watch is the drilled holes for spring bars inside the lug . they don't line up perfectly. The watch comes with 3 different wrist bands. Tungsten carbide, leather, and rubber. I always end up bending one end of the spring bar in order to fit the metal wrist band to the case. The other bands had no problem.
Other than these two problems, I like the watch. It is bright at night, looks good, and keeps good time once I adjusted the timing. It is within 5 seconds everyday.
I still wear it occasionally, but I always take it off before taking a shower.