While I'm not immune to buying things that are over the top in a multitude of ways, I bought a Pedro's Chain checker plus II(as in 2) because I needed a better chain measuring device and it had a chainring nut wrench on one end. It fits those nuts very well, no slips, and it's much longer than the horrible Park thing so you can use some leverage. I'm sure the Cyclus tool works even better but for a $100 I would rather spend money on something else as I'd rarely use it. If you have one of those knuckle scraping cranks from Sugino it would help there.
It sounds like you, Laing, use it more than I would so I can see it's value there. I was going to be buying some Cyclus tools from Europe myself, it's nice to have different manufacturers than the usual ones here.