I absolutely love SP & Company. The quality is very, very good. I would compare them to PTI quality. They stamp very well. I use SU ink with them, also Memento and have had great results. The owner is very sweet and really takes great care of her customers. I would highly recommend their stamps. Happy shopping!!
Oh...and if you go to my blog, you'll see lots of examples of SP& Co stamps. Their sentiments are a great size for cardmaking and I use them a lot.