I have a similar one and I love it. I do have a 1/4" foot but I still have to adjust my needle. Plus, I make other things that require a 3/8" and 1/2" seam allowance so I can use it to measure those as well. Mine came with one small sticky stop-bar thing but I lost it so I just use the plastic piece with the holes and use a post-it pad instead. It's not just a seam guide for guiding your fabric but it helps you set up the correct seam allowance too.
As for massdrop, I've done at least 4 drops now and never had a problem. Yes they take some time because once the buy is over, they order the product and have to distribute it. Everything I've bought was a brand name and I knew what the quality would be in advance.
eta: mine looks like this one.
http://www.connectingthreads.com/Too...e__D81716.HTML