SPD-SLs (105, in particular)

Thoughts? I realize this is an "ask five people, get five different answers" sort of question, but I thought I'd try.

My boss suggested SPD-SLs (though I think he uses the Ultegras) as an answer to my knee issues. I'm a little worried because they're quite expensive.

And in case anyone was wondering: He did say that there was a bad batch out there. (Luckily, he says, our stock is not in that batch. The only problem is that even with the employee discount, Amazon is still cheaper! Helps that I have gift cards...)