I have one of these on the shelf in the garage, but the drill gave up (the day I just bought several new blades for it, of course). It worked well for 10+ years, before dedicated circular saws were available at affordable prices. B&D had a load of drill attachments of that form. My father also had the circular saw one, but also the jigsaw and the hedgecutter attachments (and probably some I've forgotten).
However, this brings up an important point... An angle grinder spins much faster than the safe operating speed for a circular saw blade, so don't even think about going there.