I have some TiN bits and I have been happy with them. They cut quickly and cleanly. There was a recent post on the forum stating that with this type of bit, you need to avoid excessive pressure and let the bit cut on its own with just enough pressure to keep the bit moving. According to the poster, the coating is somewhat brittle and can flake off the cutting surface if too much pressure is applied. I don't have enough experience to endorse or refute this claim, but it is consistent with what I know about physics and materials science.
Bosch certainly has an excellent reputation. I don't have any of their TiN bits but I have a few Bosch power tools and router bits and they are first rate. You might want to look on Amazon.com for buyer reviews on bit sets, and for a good price on Bosch.
