It's pretty bad, but to be clear, it's not that you can't pick anything other than the default, it's that you are given a tiny selection of the biggest players and have to choose from them. Other browsers allow you to specify an arbitrary URL for it to inject the query string into.
I think Safari used to allow this. Or maybe they didn't, because I used to use something like this years ago and maybe that was when I was using chrome. Does anyone remember if Safari had this?