I love T-I strings! For me they last about a year so even with 3 mando's now in the house I don't change them very often.
The last 2 times I've experienced a problem where the black material on one or more of the wound strings comes off at the tuning peg. I've emailed T-I and I know they will send me a replacement but I'm wondering if I'm doing something wrong. I've never actually had a string break from playing but I've had this problem 2 string changes in a row.