I'm with the others. I use what works. The needle gets changed when it breaks or when I'm trying to diagnose a stitch problem. The only thing I'm a fanatic about is cleaning and oiling the machine with almost every bobbin change. Since it only needs oil in one spot, that part is easy.
I am using Groz Beckert titanium coated needles, but I don't use heavy threads, so I haven't had the problem you're describing. I prefer poly threads to cotton. I did break a needle a couple of days ago when doing machine maintenance, and it didn't shatter, just broke. Perhaps other brands of titanium needles behave differently. Have you checked to be sure that your machine is aligned so that the needle is coming down in the very center of the needle hole?