Crafty..if you are bothered by seeing your "crooked" stitches when SID...use a monofilament for the SID. I ALWAYS use it (just because I'm not as great a piecer as I would like to be and I can make "corrections" when SID using the mono and you can't see it) After I do some SID to kind of hold the quilt in place, then I do my other types of quilting.
I bought my SID foot on ebay..used it once and wish I hadn't spent so darn much time looking for it, but heck, now I have it if I ever want to use it. I generally do SID with my walking foot.