I just remembered... I went to my normal LBS today looking for a wider range cassette. I wanted a 11-32 and the guy brought it to me and told me it won't work on anything but SRAM Apex and that they have a 105 11-28. I asked what about it won't work and he was sort of short with me.. didn't really give me a clear answer. So I held off, came home, looked up the specs on some Shimano stuff and found out that it indeed would not work.

So I went to the other LBS down the street and in summary, I left convinced they were my new LBS. It felt nice feeling like I could actually have a conversation with the shop guy and leave feeling like I learned something.