Well, the Sharpening Supplies stones do offer felt-feedback, so you shouldn't have issues staying on angle, per se. But with that being said, I would recommend the Shapton Glass stones because they, too, are very fast and very hard, but they also produce just the tiniest bit of mud. It is, like, 95% metal filings, but there is just enough mud there to make it creamy feeling where the Sharpening Supplies swarf isn't. This is something that adds to my overall enjoyment of the stone. The Shapton stones are also very durable (they are not prone to surface cracks or anything like that) and they also carry with them the added convenience of splash and go. Finally, they offer my favorite finishing stones. Stropping/backhoning your edge on an 8k, or better yet, a 16k, or even a 30k SG will leave you with one of the sharpest edgest you've ever achieved.
With all that being said, I think it's generally pretty hard to make an outright bad choice with waterstones. Of all the options I've tried, while I would consider the Shapton Glass series very near--if not the--pinnacle of waterstone sharpening, the Sharpening Supplies options are far, far from the bottom of the totem pole.