One negative in my eyes is that most of their merch does seem a bit generic...I supposed you must rely on the monogram to make each item special. And all too many of the items are marked as "imported" which I suspect means "made in China." I'll suspend judgement until I see some of the product line in person, but I am slightly wary of the quality of the goods.
Nevertheless, I think Mark and Graham seems like a good source for personalized presents and for monogrammed home accessories. Let me know if you place an order...I'd love to hear what you think about the quality. It's tough with online-only shops to get a sense of that.